<PAGE>

                        MODIFICATION TO CREDIT AGREEMENT

                  THIS MODIFICATION TO CREDIT AGREEMENT (the "Modification") is
made and entered into this 26th day of January, 1998, by and among CENTRAL
SPRINKLER CORPORATION, a Pennsylvania corporation, CENTRAL SPRINKLER COMPANY, a
Pennsylvania corporation, CENTRAL CASTINGS CORPORATION, an Alabama corporation,
CENTRAL CPVC CORPORATION, an Alabama corporation, and CENTRAL SPRINKLER EXPORT
CORPORATION, a Barbados corporation, the LENDERS reflected on the signature
pages of this Modification, and CORESTATES BANK, N.A., a national banking
association in its capacity as Agent for the LENDERS.

                                   BACKGROUND:

                  A. The Lenders, the Agent, and the Borrowers have entered into
a certain Credit Agreement dated October 28, 1997 (the "Credit Agreement"),
pursuant to which the Lenders have agreed to make a revolving credit facility in
the maximum principal amount of Fifty-Five Million Dollars ($55,000,000)
available to the Borrowers, on the terms and subject to the conditions set forth
therein.

                  B. At the request of the Borrowers, the Lenders have
unanimously agreed to waive a certain Event of Default which has occurred under
the Credit Agreement provided that the Borrowers enter into this Modification
and satisfy all conditions precedent thereto.

                  NOW, THEREFORE, in consideration of the mutual promises
contained herein and other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto, intending to be
legally bound hereby, covenant and agree as follows:

                  1. Incorporation of Background; Incorporation of Credit
Agreement. The Background provisions of this Modification are incorporated
herein by reference thereto as if fully set forth in this Modification. The
Credit Agreement is also incorporated herein by reference hereto as if fully set
forth in this Modification.

                  2. Defined Terms. Any capitalized terms used in this
Modification or the Background provisions hereof which are not so defined, but
which are defined in the Credit Agreement, shall have the meanings ascribed to
those terms in the Credit Agreement.

                  3.       Additional Defined Terms.  The following defined
terms are hereby added to Section 1.2 of the Credit Agreement and
shall read in their entirety as follows:

                           "Borrowing Base" shall mean, as at any applicable
         time, (i) eighty percent (80%) of Qualified Accounts, plus


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<PAGE>



         (ii) fifty percent (50%) of Qualified Inventory, plus (iii) fifty
         percent (50%) of Net Fixed Assets, minus (iv) the aggregate outstanding
         balance of the Term Loans.

                           "Borrowing Base Certificate" shall mean a certificate
         in substantially the form of Exhibit "A-1" attached hereto and made a
         part hereof certifying as to the matters therein described.

                           "Fixed Charge Coverage Ratio" shall mean, for the
         Borrowers and the rolling four (4) fiscal quarter period ending at the
         close of the fiscal quarter of the Borrowers then in question, the
         ratio of (i) the sum of (A) net income of the Borrowers, (B)
         depreciation and amortization expense taken by the Borrowers, (C)
         interest expense on all Debt of the Borrowers, and (D) cash payments of
         the Borrowers in respect of federal and state income taxes of the
         Borrowers, to (ii) the sum of (A) principal payments due and owing in
         respect of long-term Debt of the Borrowers (excluding the Revolving
         Credit Facility), (B) payments in the nature of principal in respect of
         Capital Lease Obligations of the Borrowers, (C) the sum of the amounts
         in paragraphs (C) and (D) of clause (i) of this definition, (D) the
         aggregate amount of capital expenditures of the Borrowers not
         specifically financed with proceeds of Permitted Debt, and (E) cash
         dividends paid by the Borrowers, all of the foregoing as determined on
         a consolidated basis after eliminating all intercompany items pursuant
         to and in accordance with GAAP consistently applied; provided, however,
         (i) for purposes of calculating net income of the Borrowers under
         paragraph (A) of clause (i) of this definition, (x) the reduction to
         net income of the Borrowers resulting from the 1997 Omega Charge shall
         not be taken into account, and (y) net income of the Borrowers shall be
         reduced by any extraordinary or unusual charge (other than the 1997
         Omega Charge) taken by the Borrowers to the extent not taken into
         account in connection with the calculation of net income, and (ii) for
         purposes of calculating interest expense under paragraph (C) of clauses
         (i) and (ii) of this definition, the amount thereof shall be reduced
         (but not below zero) by the amount of interest income of the Borrowers.

                           "Net Fixed Assets" shall mean, collectively as at any
         applicable time, the sum of (i) equipment of the Secured Borrowers in
         which the Agent has a perfected first-priority security interest, and
         (ii) all other property, plant and equipment reflected on the balance
         sheet of the Secured Borrowers.

                           "Out of Trust Position" shall have the meaning
         ascribed to it in Section 2.13(c).



                                        2

<PAGE>



                           "Qualified Accounts" shall mean, collectively as at
         any applicable time, any account receivable of the Secured Borrowers in
         which the Agent has a perfected first-priority security interest where
         (i) the account is not more than ninety (90) days past the due date
         thereof, (ii) the account debtor is not an Affiliate, and (iii) the
         account is not payable from any customer located outside of the
         geographic boundaries of the United States of America, unless, with
         respect to clause (iii), payment of the account is assured by an
         irrevocable letter of credit or credit insurance issued by a United
         States banking institution or insurance company, as appropriate, and
         which is reasonably satisfactory, in all respects, to the Agent.

                           "Qualified Inventory" shall mean, collectively as at
         any applicable time, any raw materials and finished goods inventory of
         the Secured Borrowers in which the Agent has a perfected first-priority
         security interest and vet forth in the Section 1.2 of the Credit
         Agreement are hereby modified, amended, and restated to read in their
         entirety as follows:

                   4. 1997 Omega Charge. The term "1997 Omega Charge", as used
         in the definition of Fixed Charge Coverage Ratio in Section 1.2 of the
         Credit Agreement (as modified hereby), shall have the meaning ascribed
         to it in Section 12(a) hereof.

                   5. Modification to Existing Defined Terms. The following
         defined terms set forth in the Section 1.2 of the Credit Agreement are
         hereby modified, amended, and restated to read in their entirety as
         follows:

                           "Financial Covenants" shall mean, collectively, the
         affirmative covenants set forth at Sections 5.9 through 5.12 and 5.22.

                           "Revolving Credit Commitment" shall mean, as at any
         applicable time, the lesser amount of (i) Fifty-Five Million Dollars
         ($55,000,000), or (ii) the Borrowing Base, which lesser amount shall be
         the Borrowers' maximum credit availability under the Revolving Credit
         Facility, subject to reduction in accordance with the provisions of
         Section 2.1(c).

                  6. Borrowing Base Certificate. Exhibit "A-1" is hereby added
as an Exhibit to the Credit Agreement and shall be substantially in the form of
Exhibit "A-1" attached hereto and made a part hereof.

                  7. Compliance Certificate. Exhibit "B" to the Credit Agreement
is hereby modified, amended, and restated so as to take substantially the form
of Exhibit "B" attached hereto and made a part hereof.



                                        3

<PAGE>



                  8.       Voluntary Prepayments; Mandatory Payments.
Section 2.13 of the Credit Agreement is hereby modified, amended,
and restated to read in its entirety as follows:

                  "2.13  Voluntary Prepayments; Mandatory Payments.

                           (a) Except as otherwise provided herein, the
         Borrowers at any time and from time to time may voluntarily prepay any
         Base Rate Loans, in whole or in part, upon (1) one Business Day prior
         written notice to the Agent of such prepayment.

                           (b) The Borrowers shall not prepay, in whole or in
         part, any LIBOR Loan prior to the expiration of the appropriate LIBOR
         Period applicable thereto, unless such prepayment is accompanied by any
         payment required pursuant to the provisions of Section 2.3(f).

                           (c) In the event that (i) the unpaid principal
         balance of the Revolving Credit Note exceeds (ii) the Revolving Credit
         Commitment at any time (an "Out of Trust Position"), the Borrowers
         shall immediately pay to the Agent, for application to the Revolving
         Credit Note, an amount equal to the Out of Trust Position."

                  9.       Additional Condition to Advances.  Paragraph (e)
is hereby added to Section 4.2 of the Credit Agreement and shall
read in its entirety as follows:

                           "(e) Borrowing Base Certificate. The Borrowers shall
         have delivered to the Agent a Borrowing Base Certificate duly executed
         and completed by an authorized officer of the Borrowers."

                  10.      Additional Financial Reporting.

                           (a)      Additional Monthly Reports.  Section 5.1(b)
of the Credit Agreement is hereby modified, amended, and restated
to read in its entirety as follows:

                                    "(b) Monthly and Quarterly Reports: (i) as
                  soon as available, but in any event not later than thirty-five
                  (35) days after the close of each fiscal month, consolidated
                  balance sheets of the Borrowers and any Subsidiaries, as at
                  the end of such monthly period, and related consolidated
                  statements of income for such monthly period and statements of
                  cash flows for the period from the end of the preceding fiscal
                  year to the end of such monthly period, setting forth in each
                  case in comparative form the corresponding figures for the
                  corresponding period of the preceding fiscal year, together
                  with the individual balance sheets and income and related
                  statements of Central Sprinkler, Spraysafe, Castings, CPVC,
                  and all in the form heretofore


                                        4

<PAGE>



                  submitted to the CSC Board of Directors on a monthly basis and
                  prepared in accordance with GAAP applied on a consistent basis
                  (subject to normal year-end adjustments, the absence of
                  footnotes thereon and the existence of intercompany items in
                  the individual financial statements furnished in connection
                  therewith which would have been eliminated under GAAP), and
                  (ii) as soon as available, but in any event not later than
                  sixty (60) days after the close of each of the first three (3)
                  fiscal quarters of each fiscal year of the Borrowers,
                  consolidated balance sheets of the Borrowers and any
                  subsidiaries, as at the end of such quarterly period, and
                  related consolidated statements of income for such quarterly
                  period and statements of cash flows for the period from the
                  end of the preceding fiscal year to the end of such quarterly
                  period, setting forth in each case in comparative form the
                  corresponding figures for the corresponding period of the
                  preceding fiscal year, all in reasonable detail and prepared
                  in accordance with GAAP applied on a consistent basis (subject
                  to normal year-end adjustments and the absence of footnotes
                  thereon);"

                           (b)      Addition of Borrowing Base Certificate.
Section 5.1(d) of the Credit Agreement is hereby modified, amended, and restated
to read in its entirety as follows:

                                    "(d) Borrowing Base and Compliance
                  Certificates: (i) Within thirty-five (35) days after the close
                  of each fiscal month of each fiscal year of the Borrowers and
                  as required pursuant to Section 4.2(e), a Borrowing Base
                  Certificate duly executed and completed by an authorized
                  officer of the Borrowers reflecting the Borrowing Base and
                  components thereof as of the close of such month, and (ii)
                  within sixty (60) days after the close of each of the first
                  three (3) fiscal quarters of each fiscal year of the Borrowers
                  and within one hundred twenty (120) days after the close of
                  the final fiscal quarter of each fiscal year of the Borrowers,
                  a Compliance Certificate duly executed and completed by an
                  authorized officer of the Borrowers reflecting the information
                  required therein as of the close of each such fiscal quarter
                  or fiscal year, as appropriate;"

                           (c)      Omega Status Report.  Pursuant to the
provisions of Section 5.1(g), the Borrowers shall, concurrently with providing
monthly financial statements required under clause (i) of Section 5.1(b),
furnish the Agent with a status report relating to the Borrowers' liabilities in
respect of Omega fire sprinklers described in Schedule 3.10 to the Credit
Agreement, in reasonable detail and in a form which is reasonably satisfactory
to the Agent at all times. Such status report shall include, without limitation:
(i) actual expenditures incurred by


                                        5

<PAGE>



the Borrowers in respect of the Omega fire sprinklers for same monthly period
for which financial statements are then being furnished, the then current fiscal
year, and since inception of the program referred to in Section 12(a) hereof,
together with a comparison thereof to estimated expenditures for the same
periods; (ii) actual number of Omega fire sprinkler heads remediated for the
same monthly period for which financial statements are then being furnished, the
then current fiscal year, and since inception of the program referred to in
Section 12(a) hereof, together with a comparison thereof to estimated
expenditures for the same periods; (iii) the aggregate amount of cash
attributable to investments of the Borrowers and their Subsidiaries expended by
the Borrowers in connection with the program referred to in Section 12(a) for
the same monthly period for which financial statements are then being furnished,
the then current fiscal year, and since inception of the program referred to in
Section 12(a) hereof, together with a comparison thereof to estimated
expenditures for the same periods; and (v) the amount of accrued liabilities
remaining on the Borrowers' consolidated balance sheet attributable to the Omega
fire sprinklers.

                  11.      Modification to Financial Covenants.

                           (a)      Section 5.11 of the Credit Agreement is
hereby modified, amended, and restated to read in its entirety as
follows:

                                    "5.11  Minimum Cash and Investments.  The
                  Borrowers and their Subsidiaries will maintain, on a
                  consolidated basis, cash and Investments of the type
                  described in Sections 6.3(b) and 6.3(c) of not less
                  than Five Million Dollars ($5,000,000) in the aggregate
                  at all times."

                           (b)      Section 5.22 is hereby added to the Credit
Agreement and shall read in its entirety as follows:

                                    "5.22 Fixed Charge Coverage Ratio. The
                  Borrowers shall maintain a Fixed Charge Coverage Ratio of not
                  less than 1:20:1.00 as at the close of each fiscal quarter
                  (for the rolling four (4) fiscal quarter period ending as at
                  the close of such fiscal quarter) commencing with the fiscal
                  quarter ending April 30, 1998."

                  12.      1997 Omega Charge; Default Waiver.

                           (a)      Description of Omega Charge.  On or about
December 22, 1997, the Borrowers announced the recordation of an unusual charge
of Thirteen Million Two Hundred Thousand Dollars ($13,200,000) for the fourth
fiscal quarter of their fiscal year ending October 31, 1997. This charge was
recorded to reflect the expansion of a voluntary program initiated by the
Borrowers to


                                        6

<PAGE>



encourage the testing and possible replacement of certain Omega fire sprinklers.
The problems relating to the Omega fire sprinklers were initially disclosed to
the Lenders in Schedule 3.10 to the Credit Agreement (such charge being referred
to herein as the "1997 Omega Charge"). The recordation of the 1997 Omega Charge
resulted in the occurrence of an Event of Default under and pursuant to Section
7.1(n) of the Credit Agreement. The Borrowers have requested the Lenders to
waive such Event of Default.

                           (b)      Waiver of Event of Default.  Subject to the
Borrowers' execution and delivery of this Modification and satisfaction of all
conditions precedent herein contained, the Lenders hereby waive the Event of
Default which has occurred under and pursuant to the Section 7.1(n) of the
Credit Agreement solely by reason of the 1997 Omega Charge. The Borrowers
expressly acknowledge and agree that the waiver herein contained shall not, nor
shall it be deemed to, constitute (i) a waiver of any other Event of Default, or
(ii) a waiver of any Event of Default under Section 7.1(n) of the Credit
Agreement by reason of any other charge, liability, reserve, or expense which
gives rise to an Event of Default under Section 7.1(n) of the Credit Agreement
(including an additional charge, liability, reserve, or expense arising out of
or relating to the Omega fire sprinklers).

                  13. Conditions Precedent. The Lenders' agreement to grant the
waiver described in Section 12(b) hereof shall be subject to the Borrowers'
satisfaction of each of the following conditions on or before the date hereof.

                           (a)      Supporting Documents.  The Borrowers shall
have executed and delivered any and all other agreements, documents, and
instruments required by the Agent or the Lenders in connections herewith.

                           (b)      Authorizations.  The Borrowers shall have
furnished to the Agent satisfactory evidence that the transactions contemplated
hereby have been duly authorized by all requisite corporate action on behalf of
the Borrowers.

                           (c)      Other Conditions.  Such other conditions as
the Agent may reasonably impose in connection with the transactions described
herein.

                  14. Representations and Warranties. As a material inducement
for the Lenders to enter into this Modification, the Borrowers jointly and
severally make the following representations and warranties to the Lenders and
acknowledge the Lenders' justifiable reliance thereon:

                           (a)      Defaults.  Except as otherwise described in
Section 12(a) hereof, no Default or Event of Default has occurred.



                                        7

<PAGE>



                           (b)      Representations.  All representations and
warranties previously made to the Lender by the Borrowers remain true, accurate,
and complete in all material respects.

                           (c)      Enforceability.  The Credit Agreement, as
modified and amended hereby, is the valid and binding obligation of the
Borrowers and is fully enforceable in accordance with all stated terms.

                  15. Binding Effect. This Modification shall be binding upon
and shall inure to the benefit of the parties hereto and their respective
successors and permitted assigns.

                  16. Costs and Expenses. Without limiting the generality of the
provisions of Section 9.3 of the Credit Agreement, the Borrowers shall reimburse
the Agent for its out-of-pocket expenses, including reasonable counsel fees,
incurred by the Agent in connection with the development, preparation, and
negotiation of this Modification and all documents executed in connection
herewith.

                  17. Effective Date. This Modification shall be operative and
effective when the Agent and the Lenders have executed this Modification and all
conditions precedent described in Section 13 hereof have been satisfied.

                  18.      Governing Law.  This Modification shall be
governed by and construed in accordance with the domestic,
internal laws (but not the law of conflict of laws) of the
Commonwealth of Pennsylvania.

                  19.      Ratification.  Except as expressly modified and
amended herein, the Credit Agreement is hereby ratified and
affirmed.

                  IN WITNESS WHEREOF, the parties hereto have caused this
Modification to be duly executed and delivered by their proper and duly
authorized officers as of the day and year first above written.

                                     CENTRAL SPRINKLER CORPORATION

                                     By________________________________
                                              Albert T. Sabol,
                                              Executive Vice President of
                                              Finance and Administration

                                     Attest:___________________________
                                                       Secretary



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<PAGE>



                                     CENTRAL SPRINKLER COMPANY

                                     By________________________________
                                              Albert T. Sabol,
                                              Executive Vice President of
                                              Finance and Administration

                                     Attest:___________________________
                                                       Secretary

                                     CENTRAL CASTINGS CORPORATION

                                     By________________________________
                                              Albert T. Sabol,
                                              Executive Vice President of
                                              Finance and Administration

                                     Attest:___________________________
                                                       Secretary

                                     CENTRAL CPVC CORPORATION

                                     By________________________________
                                              Albert T. Sabol,
                                              Executive Vice President of
                                              Finance and Administration

                                     Attest:___________________________
                                                       Secretary

                                     CENTRAL SPRINKLER EXPORT
                                     CORPORATION

                                     By________________________________
                                              Albert T. Sabol,
                                              Executive Vice President of
                                              Finance and Administration

                                     Attest:___________________________
                                                       Secretary

                                                     ("Borrowers")

                                     CORESTATES BANK, N.A., in its 
                                     capacity as Agent

                                     By________________________________
                                              William Johnston,
                                              Vice President

                                                     ("Agent")


                                        9

<PAGE>



                                     CORESTATES BANK, N.A., individually
                                     in its capacity as a Lender

                                     By________________________________
                                              William Johnston,
                                              Vice President


                                       10

<PAGE>



                                     LaSALLE NATIONAL BANK, as a Lender

                                     By________________________________
                                              Steve Cohen, First
                                              Vice President


                                       11

<PAGE>



                                     NATIONAL CITY BANK OF PENNSYLVANIA,
                                     as a Lender

                                     By________________________________
                                              Name:
                                              Title:


                                       12

<PAGE>



                                  EXHIBIT "A-1"
                       FORM OF BORROWING BASE CERTIFICATE

----------------------------------------------------------------


                                   ----------
                                     (Date)



CoreStates Bank, N.A. (as Agent)
2240 Butler Pike
Plymouth Meeting, PA 19462-1302

Attn:  Mr. William Johnston, Vice President

Re:      Borrowing Base Certificate No. __________

----------------------------------------------------------------

Dear Mr. Johnston:

         The Borrowing Base under Section 1.2 of the Credit Agreement dated
October 28, 1997 among Central Sprinkler Corporation, Central Sprinkler Company,
Central Castings Corporation, Central CPVC Corporation, Central Sprinkler Export
Corporation, the Lenders identified therein, and the Agent (as modified, the
"Credit Agreement") was as follows on __________, 199_:


                                 BORROWING BASE

1.       Total Qualified Accounts                                     $_________
2.       80% of Total Qualified Accounts                              $_________
3.       Total Qualified Inventory                                    $_________
4.       50% of Total Qualified Inventory                             $_________
5.       Total Fixed Assets                                           $_________
6.       50% of Total Fixed Assets                                    $_________
7.       Balance of Term Loans                                        $_________
8.       Lesser of Borrowing Base (2 plus 4 plus 6 minus 7)
                  or $55 million                                      $_________
9.       Outstanding Balance of Revolving Credit                      $_________
10.      Amount Available for Borrowing under
                  Revolving Credit (8 minus 9)                        $_________



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<PAGE>



         There are no Defaults or Events of Default (as those terms are defined
in Section 1.2 of the Credit Agreement) in existence as of the date of this
letter.

         The undersigned certifies to the Agent and the Lenders that, to the
best of the undersigned's knowledge, information, and belief (based upon all
financial and related information available to the undersigned), this Borrowing
Base Certificate is a complete, accurate, and true statement of all items listed
above.

                                          ----------------------------------
                                          Executive Vice President of Finance
                                          and Administration


                                       14

<PAGE>



                                   EXHIBIT "B"

                         FORM OF COMPLIANCE CERTIFICATE

                  In accordance with the provisions of Section 5.1(c) of the
Credit Agreement (the "Credit Agreement") dated October 28, 1997, by and among
Central Sprinkler Corporation, Central Sprinkler Company, Central Castings
Corporation, Central CPVC Corporation, and Central Sprinkler Export Corporation
(together with any other Borrowers identified therein from time to time, the
"Borrowers"), CoreStates Bank, N.A. (in its capacity as Agent for the Lenders),
and the Lenders identified therein, the undersigned, ___________________, being
the Executive Vice President of Finance and Administration and authorized
officer of Borrowers, does hereby certify to the Agent and Lenders that, to best
of the undersigned's knowledge, information, and belief (based upon all
financial and related information available to the undersigned):

                  a. The representations and warranties made by the Borrowers in
Section 3 of the Credit Agreement are true and complete in all material respects
as on and as of the date hereof as if made on and as of this date;

                  b. The Borrowers have, as of the date hereof, performed all
covenants and agreements required to be performed by them under the Credit
Agreement and related Loan Documents;

                  c.       No Default or Event of Default has occurred,
[except and to the extent specifically set forth on Exhibit "A"
attached hereto and made a part hereof]; and

                  d. The Borrowers are in compliance with the Financial
Covenants set forth below.



                                          Actual                  Required

o  Adjusted Current                     ____:1.00                1.00:1.00
   Ratio (Section
   5.09)

o  Funded Debt to                       ____:1.00                 .65:1.00
   Total
   Capitalization
   (Section 5.10)

o  Minimum Cash and                      $______                 $5 million
   Investments
   (Section 5.11)

o  Tangible Net Worth                    $______                  $______
   (Section 5.12)



                                       15

<PAGE>





o   Fixed Charge                         ____:1.00                1.20:1.00
    Coverage Ratio
    (effective
    April 30, 1998)


                  e. By reason of the ratio of the Borrowers' Funded Debt to
Total Capitalization, the Applicable Margin for LIBOR Loans is in Pricing
Category ___ and shall be ___ basis points.

                  f. Borrowers are in compliance with the provisions of Section
6.1(c) and 6.1(g).

                  Any capitalized terms which are used in this Certificate and
which are not defined herein, but which are defined in the Credit Agreement,
shall have the meanings given to those terms in the Credit Agreement.

                  IN WITNESS WHEREOF, I have executed this Certificate the ____
day of _______________.

                                         By__________________________(SEAL)
                                                  Executive Vice President of
                                                  Finance and Administration of
                                                  the Borrowers


                                       16