Performance Requirements for Dual Check Backflow Preventers
|Publication Date:||1 January 2018|
|ICS Code (Check valves):||23.060.50|
|ICS Code (Water supply systems):||91.140.60|
This device consists of two
(2) independently acting check valves, internally force loaded to a normally closed position, designed and constructed to operate under intermittent or continuous pressure conditions.
The device shall be designed to accommodate the following nominal pipe sizes: ¼ NPS, ⅜ NPS, ½ NPS, ⅝ NPSM, ⅝ NPS, ¾ NPS, 1 NPSM, 1 NPS, 1-¼ NPSM, 1-¼ NPS, 1-½ NPS, and 2 NPS (8 DN, 10 DN, 15 DN, 18 DN, 20 DN, 25 DN, 32 DN, 40 DN, and 50 DN).
The device shall be designed for a working pressure of up to a minimum of 160 psi (1103 kPa).
a) Cold water service ranges from 40.0 °F to 110.0 °F (4.4 °C to 43.3 °C), or the manufacturer's maximum rated temperature, whichever is greater.
b) Hot water service ranges from 40.0 °F to 180.0 °F (4.4 °C to 82.2 °C), or the manufacturer's maximum rated temperature, whichever is greater. 1.2.5 Flow Capacity The device shall meet the minimum water flow capacities at or below the maximum pressure loss specified in Section 3.4