DESCRIPTION
The 55L-60 Pressure Relief Control is a direct acting, spring loaded,
diaphragm type relief valve. It may be used as a self-contained valve or
as a pilot control for a Cla-Val Main valve. It opens and closes within
very close pressure limits.
INSTALLATION
The 55L-60 Pressure Relief Control may be installed in any position.
The control body (1) has one inlet and one outlet port. Body (1) also has
smaller side ports; one on inlet, one on outlet, each with pipe plugs (23)
installed. These smaller side ports are used for control connections or
gauge applications. The body (1) also has one center side port, used as
the sensing line port. A flow arrow is marked on the body casting.
OPERATION
The 55L-60 Pressure Relief Control is normally held closed by the force
of the compression spring above the diaphragm; control pressure is
applied under the diaphragm.
When the controlling pressure exceeds the spring setting, the disc is lifted
off its seat, permitting flow through the control.
When controlling pressure drops below spring setting, the spring returns
the control to its normally closed position.
ADJUSTMENT PROCEDURE
The 55L-60 Pressure Relief Control can be adjusted to provide a relief
setting at any point within the range found on the nameplate.
Pressure adjustment is made by turning the adjustment screw (11) to
vary the spring pressure on the diaphragm. Turning the adjustment screw
clockwise increases the pressure required to open the valve.
Counterclockwise decreases the pressure required to open the valve.
When pressure adjustments are complete the jam nut (10) should be
tightened and the protective cap (12) replaced. If there is a problem of
tampering, lock wire holes have been provided in cap and cover. Wire
the cap to cover and secure with lead seal.
DISASSEMBLY
The 55L-60 Pressure Relief Control does not need to be removed from
the line for disassembly. Make sure that pressure shut down is accompa-
nied prior to disassembly. If the 55L-60 is removed from the line for dis-
assembly be sure to use a soft jawed vise to hold body during work.
Refer to Parts List Drawing for Item Numbers.
1. Remove cap (12), loosen jam nut (10) and turn adjusting
screw counterclockwise until spring tension is relieved.
2. Remove the eight screws (15) holding the cover (9). Keep the cover
and eight screws together and place on a suitable work surface.
See NOTE under REASSEMBLY.
3. Remove the cover (9) from body (1). The spring (8) and two spring
guides (7).
4. Remove plug (22) from body (1). Using screwdriver, hold stem
assembly (4) to remove nut (13).
5. Slide off the belleville washer (14), upper diaphragm washer (18),
diaphragm (17) and lower diaphragm washer (19).
6. Remove stem guide (21) from body (1). Remove stem assembly (4).
Inspect, replace stem assembly and/or O-rings (5), (6) and (20) if
necessary. Use soft jawed pliers or vise to hold stem. The polished
surface of stem must not be scored or scratched.
7. The seat (3) need not be removed unless it is damaged. If removal
is necessary use proper size socket wrench and turn counterclock
wise.
INSPECTION
Inspect all parts for damage, or evidence of cross threading. Check
diaphragm for tears. Check stem assembly (4) for abrasions or other
damage. Check all metal parts for damage, corrosion or excessive wear.
REPAIR AND REPLACEMENT
Minor nicks and scratches may be polished out using 400 grit wet or dry
sandpaper fine emery or crocus cloth. Replace all O-rings and any
damaged parts.
When ordering replacement parts, be sure to specify parts list item
number and all nameplate data.
REASSEMBLY
In general, reassembly is the reverse of disassembly. However, the
following steps should be observed:
1. Lubricate the O-Ring (5) and (6) with a small amount of a good grade
of waterproof grease, (Dow Corning 44 medium grade or equal).
Use grease sparingly when installing O-ring (20) into guide stem (21).
2. Install stem assembly (4) into guide stem (21). Use a rotating motion
with minimum pressure to let stem pass through O-ring. Do Not
Cut O-Ring.
3. Install O-ring (6) at top of stem assembly (4). Install guide stem (21)
and stem assembly (4) into body (1). Use socket to tighten securely.
Place lower diaphragm washer (19) on the stem assembly with the
serrated side up. Position diaphragm (17), upper diaphragm washer
(18), with serration down, and belleville washer (14) with concave
side down.
4. Install nut (13) and tighten securely .
5. Continue reassembly as outlined in disassembly steps 1 through 3.
Pressure Relief Control
55L-60
MODEL
INSTALLATION / OPERATION / MAINTENANCE
CLA-VAL
Copyright Cla-Val 2016 Printed in USA Specifications subject to change without notice.
1701 Placentia Ave
•
Costa Mesa CA 92627 Phone: 949-722-4800
•
Fax: 949-548-5441
•
E-mail: [email protected]
•
www.cla-val.com
©
N-55L-60 09/2016
SYMPTOM
PROBABLE
CAUSE
REMEDY
Fails to open
Controlling pressure
too low
Back off adjusting
screw until valve
opens
Fails to open with
spring compression
Mechanical
obstruction,
corrosion, or scale
build-up on stem
Disassemble, locate
and remove
obstruction or scale
Leakage from cover
vent hole when
controlling pressure
is applied
Diaphragm Damage
Disassemble, replace
damaged diaphragm
Loose diaphragm
assembly
Tighten upper
diaphragm washer
Fails to close
No spring
compression
Re-set pressure
adjustment
Fails to close with
spring compression
Mechanical
obstruction
Disassemble, locate
and remove
obstruction
