Cla-Val 55L - Manual

Pressure Relief Valve
Fire Protection System Service
Using the
Model 55L in a fire
protection system or other closed
type system, prevents pressure
build-up whenever line pressure
exceeds the setting of the spring.
The valve will relieve excess
pressure to atmosphere preventing
damage to the distribution network.
CLA-VAL 90-21
CLA-VAL 90-21
Model 55L
55L
Typical Applications
• UL Listed
• Factory Mutual Approved
• Direct Acting - Precise Pressure Control
• Positive Dependable Opening
• Drip Tight Closure
• No Packing Glands or Stuffing Boxes
• Sensitive to Small Pressure Variations
The Cla-Val Model 55L (UL Listed FM approved) Pressure Relief
Valve is a direct-acting, spring loaded, diaphragm type relief valve. The
valve may be installed in any position and will open and close within
very close pressure limits.
The Model 55L is normally held closed by the force of the compression
spring above the diaphragm. When the controlling pressure applied
under the diaphragm exceeds the spring setting, the disc is lifted off its
seat, permitting flow through the control. When control pressure drops
below the spring setting, the spring forces the control back to its
normally closed position. The controlling pressure is applied to the
chamber beneath the diaphragm through an external tube on the 55L.
Pressure adjustment is simply a matter of turning the adjusting screw to
vary the spring load on the diaphragm. The 55L is available in three
pressure ranges; 0 to 75 psi, 20 to 175 psi, 100 to 300 psi. To prevent
tampering, the adjustment cap can be wire sealed by using the lock
wire holes provided in the cap and cover.
Note: Also Available in Seawater Service Material
MODEL