U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
FDA Prime Connection

M-a-87: Questions Relating to the Use of Ball Type Sanitary Check Valves
 
 
HHS;PHS;FDA;CFSAN;OFP;DCP;MSB
 
                                         200 `C' Street, S.W.
                                         Washington, DC 20204
 
                                         M-a-87
 
                                         August 15, 1995 (issued)
                                         October 15, 1995 (effective date)
 
TO:         All Regional Food and Drug Directors
            Attn:  Regional Milk Specialists
 
FROM:       Acting Chief, Milk Safety Branch, HFS-626
 
SUBJECT:    Questions Relating to the use of Ball Type Sanitary Check
            Valves in HTST, HHST and Aseptic Processing Systems
 
 
1.    PMO, SECTION 7, ITEM 16p(B).2.f., FOR HTST AND HHST AND
      16p(C).2.c., FOR ASEPTIC--FLOW PROMOTING DEVICES
 
      May ball-type sanitary check valves be used as the positive shut-
      off, required by the PMO, between the flow diversion device and the
      pasteurized side vacuum equipment in a continuous flow
      pasteurization system?
 
      A. No. A ball-type check valve will only assume the blocked (shut-
      off) position when pressure for forward flow, in the pipe, is
      reversed.  In this application the positive shut-off must protect the
      flow diversion device against vacuum equipment located downstream.
      A ball-type check valve located between a flow diversion device and
      downstream vacuum equipment would be held open by vacuum from
      the downstream equipment and therefore, cannot provide the needed
      public health protection.
 
2.    PMO, SECTION 7, ITEM 16p(D), -- PASTEURIZED OR ASEPTIC PRODUCT
      IN REGENERATOR AUTOMATICALLY UNDER GREATER PRESSURE THAN
      RAW PRODUCT AT ALL TIMES
 
      May ball-type sanitary check valves be used as the positive shut off
      required by the PMO before and/or after vacuum equipment located
      on the pasteurized side of continuous flow pasteurization systems
      which contain product-to-product regenerators or which contain
      (raw) product-to-water-to-(pasteurized) product regenerators which
      are protected on the pasteurized side?
 
      A. Ball-type sanitary check valves may be used as the required
      positive shut-off when they are located after the vacuum equipment.
      Ball-type sanitary check valves shall not be used to provide the
      required positive shut-off before such vacuum equipment (see
      previous answer).
 
3.    PMO, SECTION 7, ITEM 16p(B).2.f., -- FOR HTST AND HHST AND
      16p(C).2.c.,  -FOR ASEPTIC--FLOW PROMOTING DEVICES
 
      May a ball-type sanitary check valve be used, as the required check
      valve, after an  A-C variable drive centrifugal pump in a magnetic
      flow meter based timing system?
 
      A. Yes.
 
NOTE:  Any PMO required positive shut-off found to leak is no longer
considered in compliance (applicable to the above three questions).
 
This interpretation was issued in accordance with the guidelines for
issuance of interpretations and was distributed to all state milk regulatory
and rating officials for comment.  Comments received by the NCIMS
Executive Secretary were considered by the NCIMS Executive Board and
the FDA and were incorporated into this document when it was agreed to
be appropriate.  This memorandum is effective on October 15, 1995 (60
days from the date of issue).
 
Copies of this memorandum are enclosed for distribution to State Milk
Regulatory Agencies, State Milk Rating Officers and District Milk Specialists
in your region.  This memorandum is also available on the FDA Prime
Connection computer bulletin board system and should be widely
distributed to representatives of the milk industry and all other interested
parties.
 
 
 
 
                                         Joseph M. Smucker, Acting Chief
                                         Milk Safety Branch
                                         Center for Food Safety and
                                            Applied Nutrition