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MDE-4334C Atlas Start-up and Service Manual · April 2008
Hydraulic/Mechanical Components
Vapor Recovery Stage 2 Balance Type
Inspecting Shear Valves
Always confirm proper operation of the shear valve prior to performing the hydraulic service that
requires the shear valve to be closed. In some instances, a shear valve may outwardly appear
closed but could actually be open.
WARNING
To inspect a shear valve, proceed as follows:
1
Authorize the hose at the console, as required.
2
Lift the operating handle.
3
Place the discharge nozzle in an approved container.
4
Squeeze the nozzle operating lever. If the flow continues after several seconds, it indicates that
the valve is defective.
5
Repair or replace the valve.
6
Place a few drops of SAE 10W motor oil or equivalent on the valve body shaft after testing.
Open and close the valve by hand several times. Place the valve back in service.
T-52A Pressure Regulator Valve Option
The Model T-52A PRV is a unique control valve developed for use with suction-type island
dispensers. It can be used for above ground storage tank installations, or in booster systems,
with a submersible pump in an underground storage tank.
The standard Model T-52A PRV is designed for temperatures up to -25
°
C (-13
°
F). A T-52A
cold option is available for applications where the valve must operate in temperatures between
-25
°
C to -40
°
C (-13
°
F to 40
°
F). The T-52A-Cold Valve is not for use with methanol/ethanol
applications.
Vapor Recovery Stage 2 Balance Type
Stage 2 Balance Type Vapor Recovery uses a coaxial hose and nozzle with bellows to remove
vapors. A liquid evacuation device (Venturi or Co-Vent
®
), installed in the coaxial hose,
removes liquid splashback from the vapor hose passage.
• Vapor Recovery hoses must never touch the ground when nozzle is at rest in the dispenser.
• Promptly replace damaged hoses, nozzle bellows or face seals.
• Inspect parts daily.