IM-P071-02
CMGT Issue 3
12
HP70 Series Bimetallic Steam Trap
6.2 Trap discharge temperature adjustment
This procedure is the same as that given in Section 6.1. However, prior to re-tightening the locking gland
nut, the discharge temperature may be adjusted as follows:
-
To reduce by 10
°
C (50
°F) (more subcooling), turn the screw anticlockwise
¼
turn.
-
To increase by 10
°
C (50
°F) (less subcooling), turn the screw clockwise
¼
turn.
-
Allow trap operation and condensate temperature to stabilise between adjustments.Continue adjusting
until satisfactory operation is obtained.
6.3 Trap checking
In a closed return system, a test tee (see Figure 2) and valve must be used to observe trap operation. The
trap should modulate the condensate discharge depending on inlet
temperature and pressure.
6.4 Disassembly and service
1.
Shut the trap inlet and discharge valves, vent the pressure and allow the trap to cool sufficiently to
prevent possible injury from hot surfaces.
2.
Remove the blind nut (
11
).
3.
Remove the six cover nuts (
9
) and the cover (
8
).
4.
Remove the strainer screen (
4
) and clean or replace.
5. Note:
The valve and bimetallic element assembly (
3
) is assembled loosely. Carefully lift these as one
piece from the body (
1
). Take the necessary precautions to ensure that the bimetal element arrangement
is not disturbed. Inspect the valve plug for wear.
6.
Remove the valve opening spring.
7.
Remove the valve seat (
12
) with a 36 mm A/F (1 ") pipe wrench. Inspect the valve
seating surface and the check valve seat for wear.
8.
Remove the check valve ball (
13
) and check valve spring and inspect for wear.
9.
Clean all gasket surfaces and remove dirt/scale from the trap internals with a wire brush or equivalent.
Be careful not to damage the sealing surfaces.
10.
Blow out the trap inlet piping and clean the upstream strainer if applicable.
11.
The bimetallic assembly kit (see Section 7, Spare parts) consists of the bimetallic element (
3
), valve
seat gasket (
2
), cover gasket (
7
), blind nut gasket (
10
), strainer screen (
4
), valve seat (
12
), check valve
ball (
13
) and check valve spring (
14
).
