Double check valve backflow preventer : Jandy valve actuators : Working of solenoid valves.
Double Check Valve Backflow Preventer
A backflow prevention device is used to protect water supplies from contamination or pollution.
(Backflow Preventers) Prevent drinking water from being contaminated or polluted. They are connected to a lawn sprinkler system, and are usually required by law because they are a good safety device.
A device or means to prevent backflow into the potable water supply.
check once more to be absolutely sure
Traces is a series of novels written by author Malcolm Rose, about the adventures of Forensic Investigator Luke Harding and his Mobile Aid To Law And Crime, Malc. The first book, "Framed!
countercheck: something that checks the correctness of a previous check
A device for controlling the passage of fluid through a pipe or duct, esp. an automatic device allowing movement in one direction only
A cylindrical mechanism in a brass instrument that, when depressed or turned, admits air into different sections of tubing and so extends the range of available notes
A membranous fold in a hollow organ or tubular structure, such as a blood vessel or the digestive tract, that maintains the flow of the contents in one direction by closing in response to any pressure from reverse flow
device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
control consisting of a mechanical device for controlling the flow of a fluid
a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it
PC210104
This valve is installed on the ceiling in a basement and over the entire phone system for the Motel. While it is a Double Check on a small Fire Sprinkler system, even testing or reparing the valve could destroy the entire phone line.
Cotting School
Replace defective backflow preventer with a new Apollo 6" double check valve assembly.