Series 500, HT500, 600 & HT600 expansion joints used as noise and vibration dampeners installed in unanchored piping will over-extend in response to system pressure and must be installed with control rods assemblies.

Adjust the spring mountings so the equipment is at proper elevation and level. Leave a space between pipe flanges equal to the expansion joint's face length shown on Allowable Movement and Pressure tables posted on the Arch links listed above. Install expansion joint and control rod assemblies. Control rod stop nuts should be finger tight against gusset plate. Lock in position with lock nut. Control rod assemblies will prevent extension of expansion joint and will not allow transfer of thrust load to spring supports of equipment and/or piping.

Series 500, HT500, 600 & HT600 expansion joints used to compensate thermal movement in properly anchored & guided piping systems generally do not require control rods, provided piping movements are within the allowables shown on Arch links listed above.

If, as an added precaution, designers elect to use control rods in anchored systems, the expansion joint should be installed at its exact published face-to-face length. When control rods assemblies are installed, the stop nuts should be backed away from the gusset plate a distance equal to the allowable extension of the joint (See Arch tables). This will prevent overextension of the joint. Compression sleeves should be employed. The compression sleeves are cut at the factory, to the proper length, to prevent over compression.
 

IMPORTANT:
 

a. Do not weld in vicinity of expansion joint.
b. Do not lift expansion joint by bolt holes, use
padded sling.
c. Never operate joint beyond its rated temperature pressure or movements.
( See 1 Arch, 2 Arch, 3 Arch, 4 Arch above)
d. Mating flanges must be flat or raised face. Do not mate with contoured flanges such as victualic or
similar configurations.
e. Check for chemical compatibility with the ordered material.
 

1. All pipelines must be properly supported, anchored and guided so joints do not carry pipe or thrust loads.
   
   
2. If piping is not anchored, control units must be used.
   
   
3. Use of control units and thrust sleeves will not protect piping in anchored situations. Expansion joints
   must be selected for adequate movement capability.
   
   
4. Piping should be aligned. Misalignment or improper face-to-face openings will reduce the allowable motion
   by the initial inaccuracy Joints are often damaged if forced into position.
   
   
5. Apply a thin film of graphite dispersed in glycerin or water to the rubber flange face and between the back
   up ring and the back of the rubber flange to prevent rubber adhering to the mating metal flange for easy
   removal of the joint without damage. No gaskets or gasket sealants should be used.
   
   
6. Install bolts from the back up ring side to avoid bolts projections cutting the cover. If this is impossible,
   bolts should not project more than 1/8" past the nuts. Use washers over the split ring gaps.
   
   
7. Unlike tightening hard flanges, tighten bolts in series making at least three complete circuits of each flange. Flanges will accept full bolt torque.
   
   
8. After system is in service at operating temperature, check the flange bolts and retighten as necessary.
   Repeat in a few weeks or if leaks develop. It is normal for rubber flanges to relax after initial installation.
   Check periodically until bolts remain tight.
   
   
9. Any gauges or cuts in cover during installation should be inspected and sealed.
   
   
10. If control rods are used, the clearance between the rubber washer and the gusset plate should be the
    allowable axial elongation, if the expansion joint is installed at the published face-to-face. We do not recommend precompression or extension as a general practice, but if the joint is compressed, the gap is increased by the decrease in length. If installed elongated, the gap is decreased by the increase in length.
    Hold one end against the control rod plate and the washers against the nut on the other end when measuring
    the gap.
    
    EXAMPLES
    
    6"– 500 – Allowable extension 1/2".
    
    1) 6"– 500 is installed at published 6" face-to-face dimension. Set control rod gap to 1/2".
    
    2) 6"– 500 is installed 5-3/4" long. Set control rod gap to 1/2" plus 1/4" = 3/4".
    
    3) 6"– 500 is installed 6-1/4" long. Set control rod gap to 1/2" minus1/4" = 3/4".
    
    
11. If compression sleeves are used, no setting is required as they are furnished to proper length.
    
    
12. If these instructions are not strictly adhered to, the Mercer one-year guarantee is void. Joints should be checked at a minimum of one-year intervals for signs of cracking and hardening. Expansion joints showing
    these symptoms must be replaced regardless of age.