Blagdon Pump X50 Metallic Flap Valve - Manual (Page 9)

x50fvmdl6sm-rev0612 Page 7
that the bumper stays in place allowing the sleeve to press in all the way. Reinstall the spool, opposite end cap, gasket and
bumper on the valve body. After inspecting and cleaning the gasket surfaces on the valve body and intermediate, reinstall the
valve body on the pump using new gaskets. Tighten the four hex head capscrews evenly and in an alternating cross pattern.
AIR EXHAUST
If a diaphragm fails, the pumped liquid or fumes can enter the air end of the pump, and be exhausted into the atmosphere.
When pumping hazardous or toxic materials, pipe the exhaust to an appropriate area for safe disposition.
This pump can be submerged if materials of construction are compatible with the liquid. The air exhaust must be piped above
the liquid level. Piping used for the air exhaust must not be smaller than 1" (2.54 cm). Reducing the pipe size will restrict air flow
and reduce pump performance .When the product source is at a higher level than the pump (flooded suction), pipe the exhaust
higher than the product source to prevent siphoning spills.
Freezing or icing-up of the air exhaust can occur under certain temperature and humidity conditions. Use of an air dryer unit
should eliminate most icing problems.
BETWEEN USES
When used for materials that tend to settle out or transform to solid form, the pump should be completely flushed after each
use, to prevent damage. Product remaining in the pump between uses could dry out or settle out. This could cause problems
with valves and diaphragms at re-start. In freezing temperatures, the pump must be drained between uses in all cases.
FLAP VALVE SERVICING
Valve inspection requires removal of 3/8" hex nuts and elbows. When the top suction elbows are removed, the valve and
seat are connected as an assembly. When the bottom discharge elbows are removed, the valve and seat stay with the outer
chamber. Visual inspection and cleaning is possible. If parts are to be replaced, remove the self-locking nuts and all parts
are accessible.
DIAPHRAGM SERVICING
Diaphragms can be inspected or the diaphragm assembly removed without removing the suction and discharge flanges.
Remove (8) nuts around the chamber flange, and the housing assembly will pull off. Flap valves can be inspected for proper
seating at this point as well as the diaphragm. Use care to keep foreign matter from behind the diaphragm. The opposite
diaphragm may be inspected by the same procedure. If either diaphragm has to be replaced, follow closely these steps:
Pull the outer diameter of one diaphragm off the (8) capscrews. NOTE: One side only! On the free diaphragm assembly, use a 3/8"
allen wrench to turn the assembly (diaphragm, plates and screw) loose from the shaft. Once the assembly has turned, it will turn out by
hand by use of the diaphragm. Now the opposite diaphragm assembly and the drive shaft will pull free from the capscrews and pump
intermediate assembly. The interior components consisting of sleeve bearings, rod seals, and pilot valve actuator bushings are
now accessible for service if required. Hold the shaft in a clamping device making sure to protect surface of shaft so as not to
scratch or mar it in any way. The diaphragm assembly will turn loose. To disassemble the components, turn a 1/4"-20 capscrew
by hand into the tapped hole in the inner plate. This keeps the plate from turning while the socket head capscrew is removed.
To do this, place assembly in a vise so the two protruding ends of screws are loose in the vise jaws (about 3/4" apart). Turn the
center screw loose from the back plate and the assembly will come apart.
REASSEMBLY
All procedures for reassembling the pump are the reverse of the previous instructions with further instructions as shown:
1. The diaphragm assemblies are to be installed with the natural bulge outward or toward the head of the center screw. Make
sure both plates are installed with outer radii against the diaphragm. After all components are in position in a vise and hand
tight, set a torque wrench for 480 inch pounds (40 ft. pounds) (54.23 Newton meters) or, 600 inch pounds (50 ft. pounds)
(67.79 Newton meters) for Santoprene, using a (3/8") allen head socket. After each diaphragm sub assembly has been
completed, thread one assembly into the shaft (held near the middle in a vise having soft jaws to protect the finish) making sure
the stainless steel washer is in place on the capscrew.
Make sure 1/4"-20 mounting screw has been removed and that the bumper (Item #19 on drawing) is in place in the shaft.
Install this sub assembly into the pump and secure by placing the outer chamber housing and capscrews on the end
with the diaphragm. This will hold the assembly in place while the opposite side is installed. Make sure the last diaphragm
assembly is torqued to 30 ft. lbs. (40.67 Newton meters) before placing the outer diaphragm over the capscrews. If the holes
in the diaphragm flange do not line up with the holes in the chamber flange, turn the diaphragm assembly in the direction of
tightening to align the holes so that the capscrews can be inserted. This final torquing of the last diaphragm assembly will lock
the two diaphragm assemblies together. Place remaining outer chamber on the open end and tighten down the securing nuts