2-66. SKID-MOUNTED PRETREATMENT ASSEMBLY REPAIR (CONT)
Overtightening nuts may cause gasket to pinch. Tighten nuts only until coupling halves are firmly
Tighten nuts alternately and equally until coupling halves are firmly together.
d. Check Valve Replacement/Repair
Remove rear elbow at connection C-9.
Remove reducer and nipple.
Remove front elbow.
Remove check valve from pipe.
Remove union nut.
Remove end connector and seal.
Remove ball from valve body.