Apollo Valves DC4A 설치, 운영 및 유지보수 매뉴얼 - 페이지 3

{카테고리_이름} Apollo Valves DC4A에 대한 설치, 운영 및 유지보수 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Apollo Valves DC4A 12 페이지. 1/2 inch - 2 inch double check valve (dc) backflow preventer

페이지 인쇄

DOUBLE CHECK VALVE BACKFLOW PREVENTER 1/2" – 2"

I. DESCRIPTION AND OPERATION

The Double Check Valve (DC) device consists of two independently-acting, spring-loaded check valves . Two resilient seated shut-

off valves and four test cocks complete the assembly . Each check is designed to maintain a minimum of 1 psi across the valve

during normal operation . If at any time the pressure downstream of the device increases above the supply pressure, both check

valves will close to prevent any backflow from occurring . The flowing and no flow conditions are illustrated in figures 1 and 2 .

To initiate flow, supply pressure must be sufficient to open both checks and overcome friction, normally a minimum of 3 to 5 psi

above the downstream pressure .

II. INSTALLATION

A . The DC must be installed in an accessible location to facilitate periodic field testing and maintenance .

B .

Flush all upstream piping thoroughly to remove foreign matter prior to installing the device .

C . The device should be installed either horizontally or vertical up for ease of maintenance and testing . A clearance between

the lower most portion of the device and flood grade or floor should be provided for ease of maintenance .

D . When shut-off valves are provided separately, they should be installed with a test cock on the upstream side of the inlet shut-

off valve .

E .

After installing the assembly and with downstream or #2 shut-off valve closed, pressurize the device and bleed ALL air

through test cock #4 . Then open #2 shut-off valve .

Customer Service (704) 841-6000

www.apollovalves.com

BFMM DC4A SBF