Ames Fire & Waterworks 4000CIV Cast Iron Reduced Pressure Zone Assemblies - Manual (Page 6)

6
For repair kits and parts, refer to our Backflow Pre-
vention Products Repair Kits & Service Parts price list
PL-A-RP-BPD found on www.amesfirewater.com.
Servicing the Relief Valve
Sizes: 2 1 ⁄
2
" – 10" (65-250mm)
CAUTION !
1. Remove the relief valve cover bolts. The 4000CIV is designed so
that when the bolts are backed off 1 ⁄
2
" all the relief valve spring
load is retained by the bottom plug spring module. Be sure to
verify this before removing all the bolts.
2. Remove the cover and diaphragm. The relief valve piston assem-
bly can be lifted straight up and out.
3. Replace the wiper seal and piston O-ring and apply grease to
the O-ring.
4. To replace the relief valve disc, hold the upper guide fin and
unscrew the diaphragm pressure plate. It may be necessary
to lightly tap the cast webs and the pressure plate to loosen.
Replace with a new disc holder assembly and O-ring. The disc
rubber is molded into the disc holder and is supplied as a disc
holder assembly.
5. Removal of the bottom plug and spring assembly. During normal
field service there is no need to remove the bottom plug spring
assembly other than inspection. It can be removed by simply
unscrewing with a large pipe wrench.
CAUTION !
The spring is retained on the bottom plug and is highly loaded. NO
attempt should be made in the field to disassemble the spring. For
replacement, a complete bottom plug assembly must be obtained
from the factory.
For further details contact your technical sales representative.
ClEaRanCE REQuIREd FOR
sERVICInG
in. A B
2 1 ⁄
2
– 3 10" 11"
4 15" 14"
6 15" 16"
8 23" 21"
10 25" 21"
Relief Module
B
Adapter O-ring
Diaphragm
Relief Valve Disc
Relief Valve Piston
Assembly
Piston O-Ring
Seat
O-ring
Sizes
2 1 ⁄
2
" – 3"
(65-80mm)
Diaphragm
Sizes 8", 10"
(200-250mm)
Relief Valve Assembly
Seat
O-ring
Plug & Spring
Assembly
Adapter o-ring
Diaphragm
Sizes 4", 6"
8"M1, 10"M1
(100-250mm)
Relief Valve Piston
Assembly
Piston seal
Seat
O-ring
Plug &
Spring
Piston As-
sembly
Adapter O-ring