IM-P113-04
CMGT Issue 2
10
UIB45 Sealed Inverted Bucket Steam Trap for use with Pipeline Connectors
Note: Before actioning any maintenance programme observe the 'Safety information' in Section 1.
Warning
The inner and outer gaskets used when installing/maintaining the UIB45 to a PC_ pipeline connector
contain thin stainless steel support rings which may cause physical injury if not handled and
disposed of carefully.
6.1 General information
Before undertaking any maintenance on the trap it must be isolated from both the supply line and return
line and any pressure allowed to safely normalise to atmosphere. The trap should then be allowed to cool.
When reassembling, ensure that all joint faces are clean.
6.2 Replacement of the trap unit:
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Ensure that the correct tools and necessary protective equipment are used at all times.
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Replacement of the trap unit is achieved by removing the two connector screws (
10
) and removing the trap.
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Always use new connector screws, as supplied with the new trap, when replacing a universal trap.
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The new trap unit should be positioned against the connector gasket face and apply a suitable anti-seize
thread compound to the threads of the connector screws.
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Tighten screws finger tight and ensure that the trap body is parallel to the connector.
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Tighten the screws evenly and gradually to the recommended torque (see Table 1).
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Open isolation valves slowly until normal operating conditions are achieved.
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Check for leaks.
As condensate reaches the trap it forms a water seal inside the body. The weight of the bucket keeps the
valve off its seat. Condensate can then flow around the bottom of the bucket and the trap. Under low load
or superheat conditions the trap may need to be 'primed' with water before system start-up. When steam
enters the underside of the bucket it gives it buoyancy and the bucket rises allowing the valve to seat and
stop steam escaping.
The bucket will lose its buoyancy as the enclosed steam condenses due to radiation losses and steam
escapes through the vent hole. Once this happens the weight of the bucket will pull the valve off its seat and
the cycle is then repeated.
Any air reaching the trap will also give the bucket buoyancy and close the valve preventing condensate flow.
The small vent hole in the bucket will bleed air into the top of the trap. The vent hole is of small diameter to
reduce steam loss and will consequently vent air very slowly.
Under most conditions the trap will discharge condensate with a blast type action. Under low load and/or low
pressure applications the discharge may tend to 'dribble'. Condensate is discharged at steam temperature
consequently due care must be given to the site of the discharge.
5. Operation
6. Maintenance
