4
2
6
12
13
5
10
9
1
8
4
3
19
21
20
22
17
16
18
14
15
11
7
Anderson Greenwood
SerieS 5200 POSrV
InstallatIon and MaIntenance InstructIons
Optional
sense ring
Drain port
¾ - 18NPT
Pilot
exhaust
MAIn VAlVe pArTs
Item no.
description
1
Body
2
Cap
3
Nozzle
4
Disc holder
5
Guide
6
Piston
7
Liner
8
Disc insert
9
retaining clip
10
Lower guide gasket*
11
Liner O-ring*
12
Piston O-ring*
13
Wedge ring*
14
Nut
15
Stud
16
Bracket
17
Body drain fitting
18
Upper guide gasket*
19
Sense ring gasket
20
Sense ring
21
Pitot tube
22
Body drain fitting gasket*
* included in soft goods kit. refer to Section 9 for soft
goods repair kit part numbers.
FiGUre 2 – MAiN VALVe – CONSTrUCTiON
2.2 reconditioning of main valve seats
The tightness of a valve and its proper
operation depend directly on the condition of
the seats. Many pressure relief valve problems
are due to eroded or damaged seats.
note:
before lapping the nozzle or disc, refer
to Table 3 and Table 4. Measure the parts as
shown. If the parts measure below the minimum
dimensions shown for the part, they cannot be
reused and require replacement.
The Series 5200 valve is constructed with a flat
metal-to-metal seat. it is important that seating
surfaces are refurbished properly by lapping
with a flat cast iron lap coated with the correct
lapping compound.
2.2.1 Lapping procedures
Unless the seats have been damaged badly
by dirt or scale, lapping the seating surfaces
should restore them to their original condition.
Never lap the disc insert against the nozzle. Lap
each part separately against a cast iron lapping
block of the proper size. These blocks hold
the lapping compound in their surface pores
and must be recharged frequently. Lap the
block against the seat. Never rotate the block
continuously but use an oscillating motion.
extreme care should be taken throughout to
make certain that the seats are kept perfectly
flat. if considerable lapping is required,
spread a thin coat of medium coarse lapping
compound on the block. After lapping with the
medium coarse compound, lap again with a
medium grade compound. The first step can be
omitted unless much lapping is called for. Next,
lap again using a fine grade compound. When
all nicks and marks have disappeared, remove
the entire compound from the block and seat.
Apply polish compound to another block and
lap the seat.
As the lapping nears completion, only the
compound left in the pores of the block
should be present. This should give a very
smooth finish. if scratches appear, the
cause is probably dirty lapping compound.
These scratches should be removed by using
compound free from foreign material.
Disc inserts should be lapped in the same way
as nozzles. The disc insert must be removed
from the holder before lapping. Before the disc
insert is placed back in the holder all foreign
material should be removed from both parts.
The insert must be free when in the holder.
if the disc insert is damaged too badly to be
reconditioned by lapping, it should be replaced.
re-machining the insert will change critical
dimensions, affect the action of the valve and is
not recommended.
