OPINION OF THE COURT
SEITZ, Chief Judge.The appellant sought to have declared unconstitutional the application of Pennsylvania’s postjudgment garnishment procedures to freeze her bank accounts pursuant to an attempt to garnish them. On cross-motions for summary judgment, the district court found the procedures v.alid and denied the requested declaratory relief.
I. Facts
The appellant, Mrs. Beatrice Finberg, is a 68-year-old widow whose sole source of income is social security retirement benefits. In May of 1977, Sterling Consumer Discount Co. (Sterling) sued her in Pennsylvania’s Court of Common Pleas for Philadelphia County to enforce a debt. Mrs. Finberg’s response to the suit was to write *52Sterling telling of her dependence on social security and offering monthly payments as a settlement. She never filed an answer to Sterling’s complaint.
On October 25, 1977, Sterling obtained a default judgment and immediately moved to execute on it by initiating a garnishment of the checking and savings accounts that Mrs. Finberg maintained at Philadelphia National Bank (PNB). The two accounts held a total of $550, all of which she had received as social security benefits.
The initiation of the garnishment proceeded in accordance with Pennsylvania’s rules. Sterling filed a praecipe for a writ of execution with the Prothonotary of Philadelphia County, Americo V. Córtese. Córtese issued a writ that named Mrs. Fin-berg as defendant and PNB as garnishee. He transmitted the writ to Joseph A. Sullivan, Sheriff of Philadelphia County, who served it on PNB. This service had the effect of enjoining the bank from paying out any money from the accounts. The next day, PNB mailed Mrs. Finberg a copy of the writ, and a letter informing her of the attachment of her accounts. See Pa.R. Civ.P. 3103, 3108(d), 3111, 3140(a).1
The money in these accounts was entirely exempt from attachment and garnishment. The Social Security Act provides an exemption for moneys paid as benefits. 42 U.S.C. § 407 (1976). See Philpott v. Essex County Welfare Board, 409 U.S. 413, 93 S.Ct. 590, 34 L.Ed.2d 608 (1973) (exemption protects benefits held in checking and savings accounts). In addition, Pennsylvania law grants a general $300 exemption to a class of debtors which includes Mrs. Finberg. Pa.Stat.Ann. tit. 12, § 2161 (Purdon 1967), revised and codified at 42 Pa.Cons.Stat. Ann. § 8123 (Purdon 1979).
However, Mrs. Finberg encountered some difficulties in obtaining a release of her bank accounts from attachment. Prior to the attachment, she received no notice of the garnishment action and had no opportunity to assert her exemption claims. After the attachment, no participant in the garnishment action informed her that her accounts might be exempt from garnishment or of the procedures available for obtaining a release of her exempt property. Pennsylvania law required none of these measures.
On November 18,1977, Mrs. Finberg filed a petition in the Court of Common Pleas, under Pa.R.Civ.P. 3121(d), to set aside the writ of execution on grounds of the exemption. On December 8, twenty days after the petition was filed, a common pleas judge released $300 from the accounts pursuant to the Pennsylvania exemption. The judge kept the attachment in effect for the remaining $250 so that Sterling’s attorney could take Mrs. Finberg’s deposition to determine the basis of her claim of an exemption under the Social Security Act. See Pa.R.Civ.P. 209. This deposition was taken on April 11, 1978, and Sterling agreed to the release of the remaining money on that date. The Court of Common Pleas ordered the release of this money on April 25, over five months after the filing of the petition, and PNB released the money on May 30.
II. District Court Proceedings
During the pendency of the state court garnishment proceeding, Mrs. Finberg initiated the present lawsuit in federal court to challenge the constitutionality of Pennsylvania’s postjudgment garnishment procedures. Her complaint asserts causes of action under 42 U.S.C. § 1983 (1976) and names as defendants Sterling, Sheriff Joseph A. Sullivan, and Prothonotary Americo V. Córtese.
Following the release of most of her money, Mrs. Finberg amended her complaint to focus her constitutional challenge on the attachment and freezing of her bank accounts during the pendency of the garnishment action. Pa.R.Civ.P. 3111(b, c). The complaint asserted two grounds of constitutional invalidity. First, it alleged that the imposition of the freeze without sufficient procedural safeguards for exempt *53property was a violation of due process. Second, it alleged that the attachment of accounts containing social security benefits is inconsistent with the Social Security Act exemption and hence invalid under the supremacy clause of article six of the Constitution.2
For relief, the complaint prayed for declarations that Pennsylvania’s postjudgment garnishment procedures are unconstitutional under the due process clause and the supremacy clause. On these claims, Mrs. Finberg sought relief for herself and for two classes of similarly situated plaintiffs. She made a timely motion for certification of these classes under Fed.R.Civ.P. 23(b)(2).
The defendants never answered the complaint but moved for summary judgment on all of the claims against them. Mrs. Fin-berg responded with her own motion for summary judgment. After considering these motions and the record that had been compiled, the district court entered an order disposing of all of the outstanding issues. Finberg v. Sullivan, 461 F.Supp. 253 (E.D. Pa.1978). The court found that Pennsylvania’s postjudgment garnishment procedures contain sufficient protection for the judgment debtor to satisfy the due process clause and to avoid conflict with the Social Security Act exemption. Accordingly, it granted summary judgment for the defendants on the declaratory judgment claims. As for the motion for class certification, which had been pending for more than nine months, the court concluded that its denial of relief on the merits left no purpose for certification. It therefore denied the motion.
Mrs. Finberg filed the present appeal.3 She asserts errors in the denial on the merits of the declaratory judgment claims and in the denial of the class certification motion. Two of the defendants, the prothonotary and the sheriff, have appeared as appellees to support the district court’s rulings. Sterling has not appeared as an appellee.
III. Jurisdictional Issues
Because the district court’s grants of summary judgment concluded its proceedings, we have jurisdiction to hear the appeal under 28 U.S.C. § 1291 (1976). In our deliberations, we have encountered two questions concerning the justiciability of the declaratory judgment claims against the prothonotary and the sheriff. The first is whether the prothonotary and the sheriff are properly named as defendants. The second is whether the controversy in this case has become moot.
A. Proper Defendants
A suggestion was made at oral argument that the prothonotary and the sheriff are not the proper state officials to name as defendants. Arguably, other state officials would have defended the constitutionality of the postjudgment garnishment procedures more vigorously. Our function, of course, is not to determine the most suitable defendants but to decide whether the complaint has named defendants who meet the prerequisites to adjudication in a federal court.
*54In Ex Parte Young, 209 U.S. 123, 157, 28 S.Ct. 441, 452, 52 L.Ed. 714 (1908), the seminal decision on suits to restrain the enforcement of laws alleged to be unconstitutional, the Supreme Court held that a particular official was properly named as a defendant if the official “by virtue of his office has some connection with the enforcement of the act.” So long as such a connection existed, the Court held, the suit to restrain enforcement could be characterized as a suit against the official personally and not as a suit against the state. The bar of the eleventh amendment was thereby avoided. Id. at 150-56, 28 S.Ct. at 450-452.
Ex Parte Young also explained the nature of the necessary connection. The state official sued in Ex Parte Young was the attorney general, and he had a sufficient “connection” with the enforcement of the challenged law, which set maximum rates for railroads, in his responsibility for bringing civil enforcement actions against violators. Id. at 157-61, 28 S.Ct. at 452-454. The Court reasoned that these responsibilities made him personally a party to the controversy over the law’s enforcement because his bringing of a civil enforcement action against a violator would, if the rate law was unconstitutional, constitute an actionable wrong or trespass to the violator’s legal rights. Id. at 153-56, 28 S.Ct. at 451-452. The Court cited for contrast an earlier case, Fitts v. McGhee, 172 U.S. 516, 529-30, 19 S.Ct. 269, 274, 43 L.Ed. 535 (1899), where it did not allow a suit against state officials who had no responsibilities to take any personal actions to enforce or execute a- law alleged to be unconstitutional and who consequently could commit no actionable wrong against the plaintiffs in connection with the law. See 209 U.S. at 156-58, 28 S.Ct. at 452-453.
In the present case, the duties of the prothonotary and the sheriff in connection with the postjudgment garnishment procedures consist of issuing the writ of execution and serving it on the garnishee. Pa.R. Civ.P. 3103, 3108. Their performance of these duties had the same effect on the plaintiff’s rights that the Supreme Court found critical in Ex Parte Young. Their actions were the immediate causes of the attachment and freezing of Mrs. Finberg’s bank accounts. If the rules that they were executing are unconstitutional, their actions caused an injury to her legal rights. On the basis of the reasoning employed in Ex Parte Young, we find that they are parties to her dispute over the constitutionality of these rules and properly named as defendants in her suit.
This conclusion is not altered by the fact that the duties of the prothonotary and the sheriff are entirely ministerial. Under Ex Parte Young the inquiry is not into the nature of an official’s duties but into the effect of the official’s performance of his duties on the plaintiff’s rights. We note that courts often have allowed suits to enjoin the performance of ministerial duties in connection with allegedly unconstitutional laws. See, e. g., Powell v. McCormack, 395 U.S. 486, 494, 89 S.Ct. 1944, 1949, 23 L.Ed.2d 491 (1969); Ackies v. Purdy, 322 F.Supp. 38, 40 (S.D.Fla.1970); Rodriguez v. Swank, 318 F.Supp. 289, 297 (N.D.Ill.1970) (three-judge court), aff’d mem., 403 U.S. 901, 91 S.Ct. 2202, 29 L.Ed.2d 677 (1971).
Nor do we retreat from this conclusion on any notion that these defendants have an insufficient interest in the constitutionality of the rules to be adverse to Mrs. Finberg. Once the prothonotary and the sheriff have relied on the authority conferred by the Pennsylvania procedures to work an injury to the plaintiff, they may not disclaim interest in the constitutionality of these procedures. That course of action would be inconsistent with their obligations to respect the constitutional rights of citizens. See Mattis v. Schnarr, 502 F.2d 588, 595-96 (8th Cir. 1974). In fact, the prothonotary and the sheriff have displayed no lack of interest in defending the constitutionality of the rules. They presented a successful defense in the district court and have continued a vigorous defense in this court.
If then the prothonotary and the sheriff are properly named as defendants, the suggestion that other officials should have been named is significant only if these oth*55er officials are necessary parties to the dispute. Fed.R.Civ.P. 19(a). Although the issue of necessary parties is not strictly jurisdictional, an appellate court should consider, on its own motion, any plausible argument that the interest of an absent party requires that party’s joinder. Provident Tradesmens Bank & Trust Co. v. Patterson, 390 U.S. 102, 111, 88 S.Ct. 733, 738, 19 L.Ed.2d 936 (1968).
The only other Pennsylvania officials who might be said to have an interest in this constitutional challenge to Pennsylvania’s postjudgment garnishment rules are the officials who promulgated them, the justices of the Pennsylvania Supreme Court. We find that their joinder is not necessary, even if it would be feasible. It is not necessary to afford complete relief among those already parties. Fed.R.Civ.P. 19(a)(1). A declaration that the prothonotary and the sheriff violated Mrs. Finberg’s constitutional rights would afford all of the relief that she sought at the beginning of this lawsuit: the undoing of the process that led to the attachment and freezing of her bank accounts. She requested no relief that required the involvement of the justices. Compare Ricci v. State Board of Law Examiners, 569 F.2d 782 (3d Cir. 1978) (per curiam) (Supreme Court of Pennsylvania was a necessary and indispensable party to a suit challenging a denial of admission to the state bar because a Supreme Court ruling was necessary for admission). Failure to join the justices also will not prejudice their interest in the case. Fed.R.Civ.P. 19(a)(2). Their interest is essentially the same as that of the present defendants, which is a defense of the constitutionality of the rules. From our observation of the progress of the case, we are satisfied that the prothonotary and the sheriff have performed adequately in presenting a defense. See Welsch v. Likins, 550 F.2d 1122, 1130-31 (8th Cir. 1977).
We conclude that the district court correctly proceeded with the prothonotary and sheriff as the only state officials named as defendants.
B. Mootness
Having concluded that a justiciable controversy existed between the parties at the time of the attachment of Mrs. Finberg’s bank accounts, we must decide whether the controversy became moot when she recovered all of the money that had been attached. This event removed Mrs. Finberg’s immediate personal stake in a declaration of the unconstitutionality of the application of the garnishment procedures. A finding of mootness normally would follow.
However, mootness is not the result in cases challenging “short term orders, capable of repetition, yet evading review.” Southern Pacific Terminal Co. v. ICC, 219 U.S. 498, 515, 31 S.Ct. 279, 283, 55 L.Ed. 310 (1911). To avoid mootness on this ground, a complaining party must demonstrate a “reasonable expectation” that he will be subject to a recurrence of the activity that he challenges. Weinstein v. Bradford, 423 U.S. 147, 149, 96 S.Ct. 347, 348, 46 L.Ed.2d 350 (1975) (per curiam). He also must show that the activity is “by its very nature” short in duration, “so that it could not, or probably would not, be able to be adjudicated while fully ‘live.’ ” Dow Chemical Co. v. EPA, 605 F.2d 673, 678 n.12 (3d Cir. 1979).
In the present case, Mrs. Finberg does have some reason to fear that she will suffer another attachment of her bank accounts. She remains a judgment debtor. As the record indicates that she is an elderly widow with a modest income, this judgment could remain unsatisfied for some time. Future efforts to execute the judgment are therefore likely. Sterling might repeat its attempt to garnish the accounts. For example, when new funds accumulate in the accounts, Sterling might find that the garnishment process is the most efficient way of determining whether any of the new funds are exempt. We also cannot disregard the possibility that a successor to Sterling’s interest, such as a collection agency, could make such an attempt.
Furthermore, Mrs. Finberg’s modest income and the difficulties that she has demonstrated in this case in meeting the de*56mands of a creditor indicate that she may incur another money judgment and suffer an attempted garnishment to execute it. This possibility is similar to that found adequate in SEC v. Sloan, 436 U.S. 103, 109-10, 98 S.Ct. 1702, 1707-1708, 56 L.Ed.2d 148 (1978). In Sloan, the Court found that a securities issuer’s history of violations of SEC and stock exchange rules raised a “reasonable expectation” of future violations and hence of future SEC orders to suspend trading in the issuer’s securities.
Considering all of the foregoing facts, the possibility of a future attachment of Mrs. Finberg’s bank accounts is not overwhelming, but it is not insubstantial. We conclude that she has enough of an expectation of a recurrence to satisfy this part of the test.
Mrs. Finberg also can show that any recurrence probably would evade review in this court. Any lawsuit challenging the constitutionality of the attachment would require, at the very least, one year to proceed from the filing of a complaint in the district court to the entry of judgment in this court. The attachment probably would end within that time with the occurrence of either of two events: the release of the accounts from attachment pursuant to claims of exemption, as occurred here, or the entry of a final judgment in the state court garnishment action. Pa.R.Civ.P. 3146-3148. Neither event should take as long as one year to occur because the issues and procedures in a garnishment are relatively simple. See generally Pa.R.Civ.P. 3117-3123, 3140-3148. An exceptional instance of a long and protracted garnishment is most unlikely, given the small amounts of money that Mrs.- Finberg reasonably might accumulate in her bank account. In the present case, for example, the process reached completion within six months.
We conclude that the attachment of Mrs. Finberg’s bank accounts during an attempt to garnish them was short-term activity “capable of repetition, yet evading review.” Her claims for declarations that the procedures employed in this activity violate the due process and supremacy clauses of the constitution, therefore, are not moot. Although the supremacy clause claim arises under the Constitution, it involves consideration of a state and a federal statute to determine if they conflict rather than interpretation of a substantive provision of the Constitution such as the due process clause. Therefore we normally would consider the supremacy clause claim first because, if dis-positive, it would obviate the need to decide the substantive constitutional question. See Hagans v. Lavine, 415 U.S. 528, 549, 94 S.Ct. 1372, 1385, 39 L.Ed.2d 577 (1974). However, the supremacy clause claim cannot be dispositive here because Mrs. Fin-berg claims due process violations for funds exempt under Pennsylvania law in addition to those exempt under the Social Security Act. Because of the breadth of the due process claim, we have chosen to address it at the outset.
IV. Due Process
Mrs. Finberg’s first declaratory judgment claim asserted that the attachment and freezing of her bank accounts deprived her of property without due process of law. No one disputes that Mrs. Fin-berg had a property interest in her bank accounts that required some measure of protection under the due process clause. The issue in dispute is whether the applicable rules of procedure afforded her sufficient protection.
A. Analytical Background
(1) Supreme Court precedent
The Supreme Court addressed a similar issue over fifty years ago in Endicott-Johnson Corp. v. Encyclopedia Press, Inc., 266 U.S. 285, 45 S.Ct. 61, 69 L.Ed. 288 (1924). There the Court held that due process did not require notice and an opportunity to be heard before the issuance of a writ to garnish a judgment debtor’s wages. The Court reasoned that the judgment debtor, who “has had his day in court” in the action on the merits must “take notice of what will follow.” Id. at 288, 45 S.Ct. at 62. However, the Court did not consider the possibility that the garnishment might deprive the *57judgment debtor of exempt property, which is critical to this case.
Moreover, a series of more recent decisions by the Supreme Court adopts a different line of reasoning. These decisions concern a creditor’s use of process to seize or attach a debtor’s property. They differ from the present case in that the creditor had not yet reduced its claim of indebtedness to judgment when it brought about the seizure. However, an examination of these cases will reveal that they govern the issue now before us, despite this distinction.
The first two decisions of this series established that a debtor’s interest in the continued possession and use of property must receive strong protection against the creditor’s use of process, in particular notice and an opportunity to be heard before a prejudgment seizure. Sniadach v. Family Finance Corp., 395 U.S. 337, 89 S.Ct. 1820, 23 L.Ed.2d 349 (1969), held unconstitutional a prejudgment garnishment procedure which allowed a creditor to freeze the wages of a debtor in the hands of an employer pending the outcome of the action on the creditor’s claim of indebtedness. The Court ruled that due process required notice and an opportunity to be heard before imposition of the freeze. It announced a similar holding in Fuentes v. Shevin, 407 U.S. 67, 92 S.Ct. 1983, 32 L.Ed.2d 556 (1972), which involved procedures allowing a creditor to replevy goods in which he held a security interest before a final adjudication of the debtor’s default or of the creditor’s right to repossess the goods.
The Court subsequently explained that notice and hearing prior to attachment are not absolutely necessary. Mitchell v. W. T. Grant Co., 416 U.S. 600, 94 S.Ct. 1895, 40 L.Ed.2d 406 (1974), was, like Fuentes, a review of a prejudgment seizure of goods subject to a security interest. The procedures reviewed in Mitchell required no notice and opportunity to be heard prior to seizure but afforded a number of other procedural safeguards to the debtor. These included the requirement of a sworn affidavit showing the creditor’s claim and right to repossession, issuance of a writ authorizing seizure by a judge rather than by a court clerk, the requirement that the creditor post a bond that would be used to compensate a debtor for damages caused by a wrongful seizure, and most important, notice and an opportunity for a hearing and dissolution of the writ “immediately” after the seizure. Id. at 605-06, 94 S.Ct. at 1899.
The Court held that these procedures satisfied the requirements of due process. It explained that the state has a legitimate interest in enabling the creditor to enforce his security interest in the debtor’s property. The absence of notice and a hearing prior to a seizure serves the creditor’s interest by preventing the debtor from concealing, transferring, or wasting the property. Id. at 608-09, 94 S.Ct. at 1900. At the same time, the harm that a wrongful seizure might cause was minimized by the provision for notice and hearing immediately after the seizure, and the risk of wrongful seizures in the first instance was minimized by the other procedures. Id. at 610, 94 S.Ct. at 1901. The Court concluded that with these procedures “the State has reached a constitutional accommodation of the respective interests” of the creditor and the debtor. Id.
In the final decision of this series, North Georgia Finishing, Inc. v. Di-Chem, Inc., 419 U.S. 601, 95 S.Ct. 719, 42 L.Ed.2d 751 (1975), the Court made clear that it would not find a “constitutional accommodation” unless procedures afford substantial protection to a debtor’s interest in continued use of property. This decision invalidated a prejudgment garnishment procedure that allowed the freezing of a corporation’s bank account without either notice and a hearing before the freeze or alternative safeguards similar to those in Mitchell v. W. T. Grant Co. See also Jonnet v. Dollar Savings Bank, 530 F.2d 1123, 1128-30 (3d Cir. 1976).
The case before us now presents the same interests that the Supreme Court sought to accommodate in the four prejudgment seizure cases. The attachment of property held by a garnishee is, like a prejudgment seizure, a provisional measure serving the *58judgment creditor’s interests by preventing transfer or concealment of the property before the creditor can execute a final seizure. The attachment affects the debtor’s interest by depriving her of the continued use of her property.
The fact that in this case the creditor has obtained a judgment on its claim of indebtedness does not alter this basic similarity. Sterling’s judgment represents only an adjudication of Mrs. Finberg’s liability on a monetary debt, not a transfer to Sterling of title to any particular item of her property. Sterling could obtain a final adjudication of its right to seize her bank accounts only with the completion of the garnishment process. A debtor might still defeat that right with any of a number of defenses not adjudicated in the action on the merits, such as in the present case with a claim of exemption. Thus, the attachment remains a provisional measure, and the debtor retains a protectable interest in the- use of her property during the pendency of the creditor’s action.
We conclude that the four prejudgment seizure cases control the due process issue before us now. In relying on these cases, we take the same approach to a postjudgment garnishment case that the United States Court of Appeals for the Fifth Circuit took in Brown v. Liberty Loan Corp., 539 F.2d 1355, 1365 (5th Cir. 1976), cert. denied, 430 U.S. 949, 97 S.Ct. 1588, 51 L.Ed.2d 797 (1977). See also Betts v. Tom, 431 F.Supp. 1369, 1374 (D.Haw.1977).
The principles established in the controlling Supreme Court decisions, to summarize, are that notice and an opportunity to be heard before an attachment are not absolutely necessary. However, the available procedures must afford the debtor adequate protection against erroneous or arbitrary seizures. The procedural protection is adequate if it represents a fair accommodation of the respective interests of creditor and debtor. Thus, before turning to a review of the Pennsylvania procedures, we must examine these interests.
(2) Competing interests
The relevant interests, as noted, are the creditor’s interest in enforcement of the judgment debt and the debtor’s interest in continued use and possession of her property. The weight to be accorded these interests depends upon the facts of a particular case.
The fact that the creditor has obtained a judgment establishing the monetary liability of the debtor gives it a strong interest in a prompt and inexpensive satisfaction of the debt. The creditor has the right to seek recovery from the debtor or the debtor’s property. Additional delay and expense can diminish the value of its ultimate recovery.
Another distinctive fact of this case is the type of property seized: the bank accounts of an individual. The ability to seize monetary assets advances the creditor’s interests because an execution on such assets generally is faster and less expensive than a levy and judicial sale of nonmonetary assets.
However, the debtor’s interests also assume greater weight in a seizure of an individual’s bank accounts. A bank account may well contain the money that a person needs for food, shelter, health care, and other basic requirements of life. Many people have no other immediate sources of money. Additional income from a future paycheck, welfare benefit, or other source may not be available for two weeks or more, and that income may be insufficient to meet the person’s immediate needs. When we consider the additional fact that the money in the accounts may, as here, be covered by exemptions designed to protect a debtor’s means of purchasing basic necessities, the debtor’s interest in access to a bank account becomes very compelling.
In determining whether the debtor’s protection under the Pennsylvania rules represents a proper accommodation of these interests, we must consider “the probable value, if any, of additional or substitute procedural safeguards” and the “fiscal and administrative burdens that the additional or substitute procedural requirement would entail.” Mathews v. Eldridge, 424 U.S. 319, 335, 96 S.Ct. 893, 903, 47 L.Ed.2d 18 (1976).
*59B. Review of the Pennsylvania Procedures
The Pennsylvania postjudgment garnishment procedures do not provide for notice and an opportunity to be heard before attachment of bank accounts. Mrs. Finberg concedes that due process does not require these procedures, since their absence serves the creditor’s interest in preventing a waste or concealment of assets. See Mitchell v. W. T. Grant Co., 416 U.S. 600, 608-09, 94 S.Ct. 1895, 1900, 40 L.Ed.2d 406 (1974). She contends, however, that the procedures are inadequate because they do not contain certain measures for the protection of property subject to her exemptions: an opportunity for a hearing and adjudication of claims of exemption promptly after the attachment, adequate postseizure notice to the judgment debtor, a creditor’s affidavit stating that the writ of execution will not cause the attachment of exempt property, issuance of a writ only by a judicial officer, and a bond posted by the creditor for use in compensating the debtor for an attachment of exempt property.
(1) Prompt postseizure hearing
A fundamental requirement of due process is an opportunity to be heard “at a meaningful time.” Armstrong v. Manzo, 380 U.S. 545, 552, 85 S.Ct. 1187, 1191, 14 L.Ed.2d 62 (1965). When the opportunity is deferred until after a provisional seizure of property, it must not be unnecessarily deferred much beyond that time. See Barry v. Barchi, 443 U.S. 55, 66, 99 S.Ct. 2642, 2650, 61 L.Ed.2d 365 (1979).
In the circumstances of the present case, the debtor’s interests demand an especially prompt hearing. Her purpose in asserting exemptions is to regain money required for the basic expenditures of living. The creditor, on the other hand, has an interest in delaying a hearing and adjudication on claims of exemptions only to the extent that delay is necessary to prepare a response to the debtor’s claims. At the very' minimum, then, a judgment debtor in Mrs. Finberg’s position must have an opportunity to assert and adjudicate claims of exemption promptly after the imposition of a freeze.
The appellees argue that a prompt hearing and adjudication is available on a petition to the Court of Common Pleas under Pa.R.Civ.P. 3121(d). This rule allows the court to “set aside the writ, service or levy ... (2) Upon a showing of exemption or immunity of property from execution.” Proceedings on a rule 3121(d) petition are governed by general rules of motion practice, which are Pa.R.Civ.P. 206-209 and also Philadelphia General Civil Rule 140 for Philadelphia County. Misco International Chemicals, Inc. v. Spritz, 5 Pa. D.&C.3d 779, 782-83 (Phil.Cty.C.P.1977); Hollinger v. Penn Harris Real Estate, Inc., 39 Pa. D.&C.2d 201, 205-06, 84 Dauph. 378 (1966). We find that the rules governing motion practice fail to provide a sufficient measure of promptness.
Under the Philadelphia rule, the creditor may take fifteen days to respond to a petition before the debtor may request a ruling from the court. Philadelphia General Civil Rule 140(B)(4). Even if the court then gives an immediate ruling, fifteen days is too long a period to deprive a person of money needed for food, shelter, health care, and other basic needs. The creditor has little need for this much time in preparing a response, since complicated issues seldom arise concerning the Pennsylvania $300 exemption, the Social Security Act exemption, and other exemptions designed to protect funds for basic necessities.
An exception to the fifteen-day rule is available for a “petition of an emergency nature.” Id. 140(H).4 However, nothing in the local rules, published court decisions, or *60the record of this case indicates the likelihood of a judgment debtor obtaining an exception for a rule 3121(d) petition. Nor does any authority indicate the probable length of the response period for any exception. With this much uncertainty, we cannot accept this provision as providing the necessary promptness.
Even after the period allowed for the creditor to respond, further delay is likely before the court rules on the debtor’s petition. If the creditor demands proof on any of the allegations in the debtor’s petition, which it may do by simply asserting a lack of knowledge, Pa.R.Civ.P. 1029(c), the parties must proceed to take depositions on disputed issues of fact. Id. 209(a). The motions court has no authority to dispense with the deposition process when a petition and response raise disputed issues of fact. Instapak Corp. v. S. Weisbrod Lamp & Shade Co., 248 Pa.Super. 176, 374 A.2d 1376 (1977). The rules impose no time limits on the deposition process, and it is not by nature swift. See generally Pa.R.Civ.P. 4007.-1, 4007.3. Therefore, when the creditor demands proof on claims of exemption, the rules provide absolutely no assurance of a prompt ruling on a rule 3121(d) petition.
The district court held that a debtor can obtain a prompt release of exempt property from an attachment with a request to the sheriff under Pa.R.Civ.P. 3123. The rule is quoted in the margin.5 The district court read it to mean that the sheriff, upon receipt of a verified affidavit, must “promptly” order the release of exempt funds to the use of the debtor. 461 F.Supp. at 262.
We do not read rule 3123 to apply to a judgment debtor in Mrs. Finberg’s position. A fair reading of the rule indicates that it applies to property held by the sheriff in preparation for a judicial sale. In a garnishment action against intangible property, the property stays in the hands of the garnishee until the court enters judgment against the garnishee. See Pa.R.Civ.P. 3109(a), 3111(c), 3148. The judgment then is in the form of a money judgment against the garnishee. Id. 3148(a)(1). The sheriff never holds the property in preparation for a judicial sale or for any other purpose.
We cannot find any evidence of the use of rule 3123 to claim exemptions for property held by garnishees or for executions against intangible property.6 The parties, *61one of whom is the Sheriff of Philadelphia County, state that they also are unaware of such uses. Indeed, neither appellee has offered any argument in this court in support of the district court’s assumption that Mrs. Finberg could have invoked this rule. We conclude that this assumption is incorrect.
Even in situations where rule 3123 applies, it does not provide for a prompt return of exempt property to the debtor. The rule imposes no time limit on the sheriff’s determination of the validity of a claim of exemption. No authority that we can find requires the sheriff to return exempt property to the debtor at any time before the judicial sale. We find no basis for the district court’s conclusion that rule 3123 enables a judgment debtor promptly to recover exempt property.
The only other process that might allow a judgment debtor to assert a claim of exemption is a preliminary objection to a writ of execution. Pa.R.Civ.P. 3142(a). However, proceedings on preliminary objections are subject to the same rules that govern proceedings on petitions under rule 3121(d). Pa.R.Civ.P. 1028(c); Philadelphia General Civil Rule 140(E). Hence,» this process would afford no greater promptness. We conclude that the Pennsylvania postjudgment garnishment rules fail to provide the prompt postseizure hearing and adjudication of claims of exemption under the provisions of any act of Congress or under any Pennsylvania Act of Assembly that due process requires.
(2) Notice
Along with a hearing at a meaningful time, fundamental principles of due process required that Mrs. Finberg receive timely and adequate notice of the attempt to garnish her accounts. Mullane v. Central Hanover Bank & Trust Co., 339 U.S. 306, 70 S.Ct. 652, 94 L.Ed. 865 (1950). The Pennsylvania rules provide: “Upon being served with the writ [of execution], the garnishee shall forward a copy to the defendant.” Pa.R.Civ.P. 3140(a). The rules also require the garnishee to forward to the debtor a copy of its answers to any interrogatories of the creditor. Id. 3140(b).7 Mrs. Finberg asserts two deficiencies in these procedures.
Her. first contention is that notice in the foregoing manner might not reach the debt- or. She argues that the rules do not contain sufficient safeguards against a garnishee’s failure to forward copies of the writ and answers to interrogatories.8 However, in the present case, the garnishee fully complied with the rules and gave Mrs. Fin-berg notice in the prescribed manner. The issue of this alleged constitutional defect, therefore, is not presented by the facts of this case. Accordingly, we shall refrain from considering the issue. See United States v. Rains, 362 U.S. 17, 80 S.Ct. 519, 4 L.Ed.2d 524 (1960).
The second defect that Mrs. Finberg alleges is that the notice prescribed by the rules, and received by her, did not inform her of exemptions that might apply to her property and of the process for claiming exemptions. The district court rejected this contention “since due process simply does not require that the state inform individuals of their legal rights.” 461 F.Supp. at 263.
The notice required by due process must be “reasonably calculated, under all the circumstances, to .. . afford [interested parties] an opportunity to present their objec*62tions.” Mullane v. Central Hanover Bank & Trust Co., 339 U.S. 306, 314, 70 S.Ct. 652, 657, 94 L.Ed. 865 (1950). The Supreme Court held in Memphis Light, Gas & Water Div. v. Craft, 436 U.S. 1, 13-5, 98 S.Ct. 1554, 1562-1563, 56 L.Ed.2d 30 (1978), that a public utility’s notice to customers that it was terminating gas and electric services failed to satisfy due process because the notices did not inform the customers of the process for contesting terminations. According to the Court, what due process requires for the content of the notice depends upon the circumstances of the particular case. Id. at 14 n.15, 98 S.Ct. at 1563.
In this case, Mrs. Finberg was not informed of either the exemption for social security benefits, or the $300 exemption under Pennsylvania law. As we noted earlier, both of these exemptions are designed to protect a debtor’s means of purchasing basic necessities. In a case involving an attempt to garnish an individual debtor’s bank accounts, notice that informs the debt- or of the exemption under federal law for social security benefits, of the existence of the $300 exemption under Pennsylvania law, and of the procedure for claiming these exemptions would provide substantial protection to the debtor’s interest in having funds available for basic necessities. Knowledge of these exemptions is not widespread, and a judgment debtor may not be able to consult a lawyer before the freeze on a bank account begins to cause serious hardships. These problems are probably most acute for those judgment debtors who have few immediate sources of necessary funds other than money held in a bank account. Notice of these matters can prevent serious, undue hardship for the judgment debtor whose lack of information otherwise would cause delay or neglect in filing a claim of exemption. Because Mrs. Finberg did not claim other exemptions under Pennsylvania law, we need not determine the effect of our decision on Pennsylvania exemptions not claimed by Mrs. Fin-berg.
The conveyance of this information would not place a great burden on the state. For example, the information might be provided on the copy of the writ of execution which the garnishee is required to promptly forward to the defendant. See Pa.R.Civ.P. 3140(a). The creditor would not have to incur any additional expense or delay. We hold that the failure to provide Mrs. Fin-berg with this information was a violation of due process.
(3) Preliminary affidavit, bond, and judicial issuance
The requirements of notice and an opportunity to be heard on claims of exemptions after the imposition of a freeze, as just discussed, serve to minimize the hardship caused the debtor by an attempt to garnish exempt funds. Mrs. Finberg argues that due process requires a number of additional procedures that arguably would reduce the number of such garnishments in the first instance.
The first of these procedures is a requirement that the judgment creditor file, along with the praecipe for a writ of execution, an affidavit stating that the writ would not cause the attachment of exempt funds. Mrs. Finberg next contends that two additional procedures are necessary to reduce the number of wrongful garnishments: the posting of a bond to compensate the judgment debtor for injury caused by attachment of exempt property and the requirement that a judge or magistrate issue a writ of execution.
We have considered these contentions and conclude that although the requirements might be desirable, we do not believe their absence constitutes a violation of due process. See Brown v. Liberty Loan Corp., 539 F.2d at 1369.
V. Supremacy Clause
Mrs. Finberg’s second declaratory judgment claim asserted that the Pennsylvania postjudgment garnishment rules conflict with the Social Security Act exemption. She prayed for a declaration that the procedures are invalid under the supremacy clause of article six of the Constitution.
*63A state law is in conflict with a federal statute, and void under the supremacy clause, if it “stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress.” Hines v. Davidowitz, 312 U.S. 52, 67, 61 S.Ct. 399, 404, 85 L.Ed. 581 (1941). Accord, Jones v. Rath Packing Co., 430 U.S. 519, 526, 97 S.Ct. 1305, 1310, 51 L.Ed.2d 604 (1977). This test requires us to examine first the purposes of the federal law and second the effect of the operation of the state law on these purposes. See Perez v. Campbell, 402 U.S. 637, 91 S.Ct. 1704, 29 L.Ed.2d 233 (1971).
The Social Security Act exemption provides that benefits “shall not be subject to execution, levy, attachment, garnishment, or other legal process.” 42 U.S.C. § 407 (1976). The overall objective of the social security system is “the protection of its beneficiaries from some of the hardships of existence.” United States v. Silk, 331 U.S. 704, 711, 67 S.Ct. 1463, 1467, 91 L.Ed. 1757 (1947). The exemption of benefits from legal process has the apparent purpose of furthering this objective by ensuring that a beneficiary has uninterrupted use of moneys received as benefits.
The immediate effect of Pennsylvania’s current postjudgment garnishment procedures is to provide a judgment creditor with a means of violating the exemption. Social security beneficiaries commonly hold their benefits in bank accounts. Yet, the Pennsylvania procedures make available a process for attaching and freezing bank accounts without regard to whether they contain social security funds.
Even though the procedures have this effect, they might still avoid interference with congressional purposes if they operate in a manner that avoids any significant interruption of access to benefits. However, as our discussion in the previous section illustrates, they do not operate to avoid such consequences. The absence of a prompt hearing on claims of exemption means that a judgment debtor could be denied access to social security benefits for a long time. The inadequate notice procedures raise a danger of a permanent loss of benefits. For a judgment debtor who depends upon social security to meet the necessary expenditures of living, these consequences can be severe.
Thus, the net effect of Pennsylvania’s postjudgment garnishment procedures is to bring about precisely the consequences that Congress sought to prevent. It follows that they stand “as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress.” Hines v. Davidowitz, supra.
The district court sought to avoid this conclusion with a special reading of the Pennsylvania procedures. The court presumed that the draftsmen of the rules did not intend that they be used to attach and freeze Social Security benefits. It then concluded that such use of the procedures was a violation of Pennsylvania law, “so that one who proceeds with such a garnishment will be liable for the return of the unlawfully seized, federally exempt funds.” 461 F.Supp. at 258.
We need not determine the correctness of the district court’s reading of Pennsylvania law because we find that even under this reading the postjudgment garnishment procedures would still operate to frustrate congressional purposes. A creditor already must return social security benefits that have been attached; the mechanism is a petition to set aside the writ of execution under Pa.R.Civ.P. 3121(d). The addition of a formal prohibition of the attachment of benefits and “liability” for their return would add no greater sanction against this use of the garnishment procedures. The creditor would have no reason to take any greater care to avoid the attachment of bank accounts that contain social security benefits than he would take without these measures. The measures contemplated by the district court would be no more than formal and ineffective barriers to interference with congressional purposes.
We conclude that the Pennsylvania procedures conflict with the social security exemption and are invalid under the supremacy clause.
*64VI. Class Certification
Mrs. Finberg filed a timely motion to certify a plaintiff class and subclass for the declaratory judgment claims. The district court took no immediate action on the motion but left it pending for nine months. Eventually the court found that the declaratory judgment claims lacked merit. Having reached this conclusion, it reasoned that “class certification would serve no purpose” and denied the motion. 461 F.Supp. at 257.9
We note that our vacating of the summary judgment orders on the declaratory judgment claims removes the premise for the district court’s denial of class certification. However, we believe the merits of the plaintiffs’ substantive claims to be an impermissible basis for deciding this issue.
It is not correct to say that the district court’s ruling on the merits of the declaratory judgment claims deprived certification of any purpose. In general, the certification of a class does not depend upon whether the substantive claims have any merit. Eisen v. Carlisie & Jacquelin, 417 U.S. 156, 177-78, 94 S.Ct. 2140, 2152, 40 L.Ed.2d 732 (1974); Kahan v. Rosenstiel, 424 F.2d 161, 169 (3d Cir.), cert. denied, 398 U.S. 950, 90 S.Ct. 1870, 26 L.Ed.2d 290 (1970). Certification in suits for injunctive or declaratory relief under rule 23(b)(2) serves an important purpose that is not obviated by rulings against the named plaintiffs on the substantive claims. Because a risk of mootness often is present in these cases, certification ensures that the claims of unnamed plaintiffs will receive full appellate review. If the claims of the named plaintiffs become moot, the appellate court might still find that the claims of unnamed class members present live controversies. Sosna v. Iowa, 419 U.S. 393, 398-402, 95 S.Ct. 553, 556-558, 42 L.Ed.2d 532 (1975). The Supreme Court recognized the importance of this function of rule 23(b)(2) certification when it stated that the district court should “heed strictly” the requirement of a prompt ruling on a certification when mootness may develop. Swisher v. Brady, 438 U.S. 204, 213-14 n.11, 98 S.Ct. 2699, 2705-2706, 57 L.Ed.2d 705 (1978).
We hold that the district court’s rulings on the plaintiffs’ substantive claims did not constitute a valid basis for denial of class certification. We will vacate the denial of class certification.
VII. Conclusion
The orders of the district court granting summary judgment for defendants on each of the declaratory judgment claims and denying class certification will be vacated. The case will be remanded to the district court for disposition consistent with this opinion.
. The term “garnishment” refers to the process of execution against property held by someone other than the debtor. “Attachment” refers to the seizure imposed on property held by a garnishee at the beginning of the garnishment process.
. The amended complaint substituted for Córtese his successor as prothonotary, John Pettit, and the district court entered judgment in Pettit’s name. See Fed.R.Civ.P. 25(d)(1). However, the dockets of the district court and of this court still name Córtese as the defendant prothonotary, and counsel for the prothonotary still refer to their client as Córtese. Although the proceedings following the substitution should have been in Pettit’s name, we may disregard “any misnomer not affecting the substantial rights of the parties.” id.; Fed.R. App.P. 43(c)(1). No one has suggested that the continued reference to Córtese as prothonotary has affected substantial rights. We take note of the practice only to avoid confusion.
. In a third claim, Mrs. Finberg sought damages of $23.50 from Sterling as compensation for an amount that PNB retained as fees for its services as a garnishee. The district court awarded this relief. Sterling has not seen fit to appeal such award.
The amended complaint also named three other individuals as additional plaintiffs on the declaratory judgment claims. The district court’s final order included a grant of summary judgment for defendants on these plaintiffs’ claims as well. These plaintiffs have not appealed.
. The sheriff argues that the judgment debtor can invoke Philadelphia Court Rule 20, which makes a judge available on evenings and weekends for emergency matters like urgent petitions for temporary restraining orders. Assuming that a debtor can invoke this rule to assert an exemption, the ability to file a rule 3121(d) petition at night or over a weekend, rather than wait for the next business day, will not shorten the 15-day period by very much. We find nothing in rule 20 that allows a judge to dispense with the 15-day period of rule 140.
. Pa.R.Civ.P. 3123:
(a) A defendant entitled to a statutory exemption may claim it in kind or in cash at any time before the date of sale by notifying the sheriff of his claim and, if the exemption is claimed in kind, by designating the property which he elects to retain as exempt....
(b) Upon receipt of a claim for exemption in kind the sheriff shall set aside, from the designated property, enough thereof as appraised by him, to equal the value of the exemption, unless the property is incapable of division. In the event of failure of the defendant to claim his statutory exemption, the sheriff shall similarly choose, appraise, and set aside property in kind....
(c) If the sheriff cannot set aside property in kind because the property in his hands is not capable of appropriate division, he shall set aside from the proceeds of the sale and pay to the defendant in cash the amount of his statutory exemption.
(d) Any party in interest may, within forty-eight (48) hours, appeal to the court from the sheriff’s appraisal or designation of property. The sheriff shall proceed with the sale as to the remainder of the property levied upon unless the sale shall be stayed by order of the court or written direction of the plaintiff.
. Prior to the adoption of the current rules in 1960, a process similar to rule 3123 was available for submitting claims of exemption directly to the sheriff. § 2 of the Act of April 9, 1849, P.L. 533, 12 Pa.Stat.Ann. § 1262 (Purd'on 1967) (repealed 1978). See Pa.R.Civ.P. 3241(54) (suspended use of this process in 1960 for proceedings to execute money judgments). The Pennsylvania Supreme Court recognized that this process had no application in a garnishment of a debt because the sheriff does not hold the debtor’s property in preparation for a sale. Bancord v. Parker, 65 Pa. 336, 337-38 (1870). Our reading of rule 3123 is essentially the same.
Under the old process, the judgment debtor could claim an exemption for intangible property frozen in the hands of a garnishee either by notifying the sheriff of the claim when the sheriff served him, the debtor, with the writ of execution, or by asserting the claim in court during proceedings on the garnishment. Id. at 338. See also Hild Floor Machine Co. v. Rudolph, 156 Pa.Super. 102, 39 A.2d 457 (1944). The first of these opportunities, notice to the sheriff at the time of service, has no counterpart under the current rules because the sheriff does not serve the debtor. See Pa.R.Civ.P. *613111(a), 3140(a). The second opportunity, assertion of the claim to a court, has a counterpart in rule 3121(d).
. The garnishee “forwards” a document to the debtor either by serving it on a competent adult in accordance with the rules for serving a writ of summons or by sending it to the debtor’s last known address by registered mail. Pa.R.Civ.P. 3140(c).
. The rules give the garnishee an incentive to forward these documents by holding that the garnishee “shall thereafter be under no duty to resist the attachment or defend the action against the defendant in any manner.” Pa.R. Civ.P. 3141(a). They do not provide that a failure to forward documents shall subject the garnishee to contempt of court. Nor does a failure affect the judgment creditor’s right to proceed with the garnishment. Mrs. Finberg’s argument rests on the absence of such provisions. ■
. The district court also found it “doubtful” that the proposed classes shared common questions of law or fact, as required by Fed.R.Civ.P. 23(a)(2). 461 F.Supp. at 257 n.7. The complaint proposed a class of judgment debtors in Philadelphia with “legal or equitable defenses to set aside the execution” and a subclass of debtors holding property exempt “by virtue of federal law.” The district court explained: “The broad spectrum of federal and state exemptions that may be claimed in a Pennsylvania garnishment proceeding implicates a correspondingly broad spectrum of factual scenarios, only a fraction of which is spanned by the facts presented in this case.” Id.
Whether or not this statement reflects a proper application of the common questions requirement of rule 23(a)(2), or of the typicality requirement of rule 23(a)(3), we cannot rely on it to uphold the denial of class certification. The problem identified by the district court might well be remedied by requiring a more specific or a narrower definition of classes. The district court should not deny certification on account of such problems without considering the possibility of redefining the classes. See Bogosian v. Gulf Oil Co., 561 F.2d 434, 453 (3d Cir. 1977), cert. denied, 434 U.S. 1086, 98 S.Ct. 1280, 55 L.Ed.2d 791 (1978); Samuel v. University of Pittsburgh, 538 F.2d 991, 995-96 (3d Cir. 1976).