Lower Diaphragm Maintenance; Upper Diaphragm Maintenance; Type Sa/2 - Emerson Tartarini PRX Series Instruction Manual

Lower Diaphragm Maintenance

1. Disconnect pilot and remove it from the line.
2. Remove machine screws (key 10) from lower cover
(key 21) and the separate lower cover from the body
(key 16).
3. Use a wrench to hold the stem (key 23) and break loose
the stem nut (key 20). Remove the stem nut and washer
(key 11).
4. Remove the upper diaphragm plate (key 13),
diaphragm (key 14), lower diaphragm plate (key 15)
and O-ring (key 18). Inspect parts for damage or
wear, replace if necessary.
5. Lightly lubricate the O-ring (key 25). Place O-ring over
the stem (key 23) and press it down into the body
(key 16).
6. Lightly lubricate the rims of the diaphragm (key 14)
and place it on top of the lower diaphragm plate
(key 15). Set the upper diaphragm plate (key 13) on the
diaphragm (key 14).
7. Lightly lubricate the O-ring (key 18) and place it in the
lower cover (key 21).
8. Place the washer (key 11) and stem nut (key 20) on
the stem (key 23) and tighten. If also performing Upper
Case Maintenance, skip to step 2 of the Upper Case
Maintenance section.
9. Insert washers (key 11) and machine screws
(key 10) in the lower cover (key 21) and tighten uniformly
to ensure proper seal.

Upper Diaphragm Maintenance

1. Disconnect pilot and remove it from the line.
2. Loosen locknut (key 2) and back out adjusting screw
(key 1) until compression is removed from the spring.
Remove cap (key 3).
3. Lift the upper spring seat (key 6), spring (key 7) and O-ring
(key 4) out of the upper cover (key 8). Inspect O-ring and
replace if necessary.
4. Remove the machine screws (key 10) and the washers
(key 11), separate the upper cover (key 8) from the
body (key 16) and lift the lower spring seat (key 9) away
from upper diaphragm nut (key 26). Use a wrench to
hold stem (key 23) securely while removing the upper
diaphragm nut.
5. Remove remaining loose components: washer (key 11),
upper diaphragm plate (key 13), diaphragm (key 14),
disk holder (key 22) and O-ring (key 18). Inspect
diaphragm and O-ring for damage or wear and replace
if necessary.
6. Remove orifice (key 19) and O-ring (key 17). Inspect
the parts for damage or wear and replace if necessary.
Lightly lubricate the O-ring and place in the body
(key 16). Install the orifice.
7. Set the disk holder (key 22) in the body (key 16).
8. Lightly lubricate the rims of the diaphragm (key 14).
Position the diaphragm convolution facing down, make
sure that the diaphragm is not deformed and is properly
installed. Take the diaphragm (key 14) and place it in the
body (key 16) on top of the disk holder (key 22).
9. Set the upper diaphragm plate (key 13) on top of
the diaphragm (key 14).
10. Place washer (key 11) and stem nut (key 26) on the
stem (key 23) and tighten using a wrench to hold
the stem.
11. Place the upper spring seat (key 9) on the upper
diaphragm nut (key 26) and mount the upper cover
(key 8) on top of the body (key 24) and the diaphragm
(key 14).
12. Place washers (key 11) and uniformly tighten the machine
screws (key 10) to hold the body (key 24) and upper cover
(key 8) together.
13. Install spring (key 7) and upper spring seat (key 6) on
top of the lower spring seat (key 9) inside the upper
cover (key 8). Install cap (key 3).
14. Screw in adjusting screw (key 1) at desired spring
compression and use the lock nut (key 2) to lock the
adjusting screws position.
Type SA/2 (Figure 5)
1. Disconnect pilot supply filter regulator and remove it from
the line.
2. Remove cap screws, washers and nuts (keys 2, 9 and
10) from body (key 7) and separate upper and lower
covers (keys 11 and 19) from the body (key 7). When
separating the covers from the body, be aware of loose
components: (keys 1, 3, 4, 8, 12, 18, 20 and 21).
3. Remove and inspect O-ring (key 13) for damage or wear
and replace if necessary. Lightly lubricate the O-ring
before placing it back in the filter cover (key 11).
4. Clean filter nets (key 8). Replace filter pad (key 12).
5. Inspect diaphragm (key 18) for damage or wear and
replace if necessary. Check the seating surface of the
screw unit (key 17) for erosion, scratches, spurs or other
damage and replace if necessary.
6. Unscrew and remove the regulator seat (key 5). Inspect
O-ring (key 6) for damage or wear and replace if
necessary. Lightly lubricate the O-ring and place it on the
regulator seat.
7. Pull pad holder unit (key 15) out of the body (key 7).
Inspect the seat for damage, replace if necessary.
8. Set the pad holder unit (key 15) on the spring
(key 14) and insert the regulator seat (key 5). Tighten the
regulator seat until it stops.
PRX Series
7