Ames Fire & Waterworks 6000HMB Portable Hydrant Meter Backflow Preventers with Meter Housing - Manual (Page 5)

Relief Valve Reassembly
1. Thoroughly clean all inside surfaces of the relief valve body.
2. Inspect the relief valve body seat surface located at the top
edge of the 3 discharge slots near the top of the body by rub-
bing the end of the index finger around the entire seat surface;
access the seat surface through the slots or the bottom of the
body. The seat must be free of nicks. If nicks are discovered,
remove the body & install a new relief valve assembly.
3. Position the diaphragm on the piston assembly so that it is fac-
ing up as shown in Figure 8.
4. Now fold the top (ribbed) edge of the diaphragm inward, grasp
the sleeve with the ribbed edge up and slide the sleeve down
over the piston assembly as shown in Figure 8.
5. While still holding the sleeve, slide it up over the diaphragm and,
using your thumb & index finger, position the bead of the dia-
phragm so that it wraps over the outside of the rib on the top
of the sleeve so that the sleeve is held by the diaphragm. Now
place the piston assembly on a flat, firm surface with diaphragm
facing up as shown in Figure 9.
6. Cup your hand slightly to form an air trap and force the sleeve
down over the piston assembly with a rapid slap (hard) on
the open end of the diaphragm with your cupped hand. The
trapped air in the diaphragm will force the diaphragm between
the inside of the sleeve and the outside of the piston. Ensure
that the diaphragm is fully seated by running the end of a dull
“butter” knife in the formed diaphragm. If diaphragm is wrinkled,
repeat previous step.
7. Slide the piston assembly and sleeve into the relief valve body
with the hex head bolt entering the flanged end of the body
first. Slide the piston assembly in until the diaphragm lip is
smoothly seated in the machined groove in the flanged end of
the body. By running your index finger around the outside of
the diaphragm bead, you will ensure it is seated smoothly.
8. Position the bottom flange cover on the bottom of the relief
valve body and secure by hand tightening the 4 bottom bolts.
9. Now tighten the 4 bottom bolts to approximately 15 ft.-lbs. with
a 5 /
16
" socket or open-end wrench.
10. Reattach the relief valve hose to the elbow in the bottom flange
cover.
5
Figure 6
Item # Part Description
21. Relief Valve Body
22.* Rubber Shut-Off Disc.
23.* Piston Diaphragm Assembly
24. Hex Head Bolt
25. Disc. Retainer
26. Sleeve
27. Bottom Bolt
28. Bottom Flange (w/St. Elbow)
29. Elbow St 90 3/8
30.* O-Ring Disk
31. RV Spring
Figure 9
Figure 6
Figure 7
Figure 8
Relief Valve
31
21
22
24
30
25
26
28
29
23
27