N.J. Admin. Code § 7:10-10.3

Current through Register Vol. 56, No. 24, December 18, 2024

Section 7:10-10.3 - Approved physical connection installation requirements

(a) An approved physical connection installation shall be either a double check valve assembly or a reduced pressure zone backflow preventer assembly, as defined at N.J.A.C. 7:10-1.3, designed and constructed in accordance with the requirements of this subchapter.

(b) The approved physical connection installation shall be a reduced pressure zone backflow preventer assembly when the unapproved water supply is a non-potable water source or a source in which contaminant levels measured pursuant to the State primary drinking water regulations at N.J.A.C. 7:10-5 exceed the maximum contaminant levels specified therein.

(c) The requirements of (b) above shall not apply to any physical connection installation operated under a current physical connection permit issued before November 18, 1996 until such time as the existing physical connection is replaced or modified.

(d) Each backflow prevention device used in an approved physical connection installation shall be constructed as follows:

1. For devices up to and including two inches in diameter, the double check valve assembly or the reduced pressure zone backflow preventer assembly shall be of durable, non-toxic plastic, or of all stainless steel, all bronze, or all brass construction;

2. For devices larger than two inches in diameter, the double check valve assembly or the reduced pressure zone backflow preventer assembly shall be constructed as described in (d)1 above or shall be constructed of cast iron or steel, lined with brass, bronze, epoxy resin, stainless steel, or other durable nontoxic, non-corrodible material acceptable to the Department;

3. The clappers, discs or poppets, hinges, bushings, and seatings of the check valve assemblies in any device used for an approved physical connection installation shall be constructed of brass, bronze, stainless steel or non-toxic plastic, and shall be so designed and installed as to be readily replaceable;

4. Facing rings of the clappers, poppets or discs, or differential relief valves shall be composed of durable molded natural rubber, synthetic rubber or neoprene, shall be of even thickness, smoothfaced, water-absorption resistant and shall provide a positive seal against the backflow of water through the device;

5. Every double check valve assembly and reduced pressure zone backflow preventer assembly shall have test cocks installed to facilitate the pressure testing required pursuant to N.J.A.C. 7:10-10.6;

6. Every backflow prevention device up to two inches in diameter shall be installed with full port ball type shutoff valves. For backflow prevention devices that are larger than two inches in diameter, shutoff valves of the ball valve type are recommended. Strainers installed upstream of the leading shutoff valve are recommended for all backflow prevention devices regardless of sizes; and

7. The pipe conveying water from the differential relief port of a reduced pressure zone backflow preventer assembly shall allow an air gap between the assembly and the drain pipe, and the pipe shall be of the same diameter as, or larger than, the relief port.

(e) All approved physical connection installations shall meet the following operating conditions:

1. The turbulence in the backflow prevention device shall not be excessive for flow rates up to the rated flow so as not to interfere with proper operation of the device;

2. All moving parts shall be designed to operate up to the rated flow in a positive manner without chatter;

3. The backflow prevention device shall not cause water hammer, nor be adversely affected by water hammer arising from an outside condition; and

4. The backflow prevention device shall not permit leakage in a direction reverse to normal water flow.

(f) In addition to the operating conditions set forth at (e) above, all double check valve assemblies shall, under normal flow conditions, operate so that the independently operating check valves remain closed until there is a demand for water. Each of the check valves in series must maintain a minimum of one psi pressure differential in the direction of flow. If, at any time, pressure downstream of the device increases to within one psi of supply pressure, both check valves must close to prevent backflow.

(g) In addition to the operating conditions set forth at (e) above, all reduced pressure zone backflow preventer assemblies shall, under normal flow conditions, operate so that both check valves are open and the pressure area between the check valves, called the zone, is at least five psi lower than the supply pressure. The relief valve, within the zone, is held shut by supply pressure acting through an internal sensing passage on the relief valve diaphragm. The first check valve in the line of flow must maintain a minimum pressure differential of five psi and the second check valve in the line of flow must maintain a minimum pressure differential of one psi. If the first or second check valve becomes fouled, the pressure in the zone will increase causing the relief valve in the zone to open automatically and discharge to the atmosphere in order to maintain a pressure in the zone which is at least two psi lower than the supply pressure, thus preventing backflow.

N.J. Admin. Code § 7:10-10.3

Amended by R.2000 d.354, effective 8/21/2000.
See: 31 N.J.R. 2717(b), 32 N.J.R. 3106(a).
Rewrote (b); and in (d)6, added a third sentence.