Pressure Creep | Diaphragm Replacement

Pressure Creep

Pressure creep is caused by contaminants of some kind in the diaphragm of the regulator.

A common reason for pressure creep is if liquid is inadvertently introduced into the gas line. The liquid will then enter the regulator diaphragm and cause pressure creep.

Pressure creep is quite easy to diagnose.

If the adjustment knob of the regulator is would out completely (so either removed from the spindle or wound as far anti-clockwise as possible) but the low-pressure gauge of the regulator still increases in pressure, this is 'pressure creep'.

Typically the pressure will creep up quite quickly until the PRV starts to release. if not corrected, it is quite easy to lost an entire cylinder of gas as a result of pressure creep. it can also lead to over carbonated beverages in the keg.

Pressure creep is both easy to identify and correspondingly easy to fix.

To correct pressure creep, the diaphragm will need to be replaced (MK4 regulator models) or the seat cap assembly may need to be cleaned or the diaphragm replaced (MK5 regulators).

KegLand MK4 and MK5 regulators are made with a fully encapsulated seat and seat cap design. This design makes it easier to service the regulator and also further reduces the chance of pressure creep. In addition, the MK5 regulator has a check valve built into the gas outlet ball valve

Even with excellent regulator design and several preventative measures it is still possible for pressure creep to occur and this manual has been written to describe how to resolve this issue.

The process is different depending on the model of regulator.

MK4 regulators will require a replacement diaphragm.

Due to their unique design, MK5 regulators generally require diaphragm maintenance/cleaning.

Diaphragm Replacement (MK4 regulators)

The correct diaphragm for all MK4 Regulators is KL15646 MK4 - Replacement Regulator Diaphragm and Seat Assembly

1

Remove the Bonnet

Using a large wrench or spanner, remove the bonnet (standard thread, so unscrews anti-clockwise)

2

Identify Brass Seat and Cap assembly, remove button

Once the bonnet has been removed you will seat the seat cap assembly. Carefully remove the button from the middle of the assembly

3

Remove Seat Cap assembly

Using a 16mm socket, unscrew and remove the Seat Cap assembly as shown

4

Install new Seat Cap assembly

Insert the new seat and seat cap assembly making sure that all surfaces and parts are extremely clean. Contamination in any of these components might cause the problem to reoccur.

Once the new seat and seat cap assembly is installed re-insert this back into the regulator body and tighten with a 16mm socket. Ensure the button is installed in the new Seat Cap assembly (refer Step 2)

5

Replace Bonnet

Replace the bonnet by tightening this clockwise onto the regulator body. If the diaphragm and spring assembly needs replacing or came out of the bonnet during removal refer to the below image for correct installation

6

Perform a Pressure Decay Test

Perform a Pressure Decay Test to ensure that the diaphragm replacement was sucessful

Diaphragm Maintenance (MK5 Regulators)

Due to their unique, modern design, unlike most regulators on the market the MK5 Regulator diaphragm does not generally require replacement in the event of preessure creep. It can be removed and cleaned instead. In the event that it has sustained damage it can be replaced quite inexpensively however. The procedure is broadly similar.

For a video guide to maintaining a MK5 diaphragm in the event of pressure creep please see below.

In the event that the seat cap assembly needs to be replaced they can be purchased here: KL30663 MK5 - Regulator Replacement Diaphragm & Seat Assembly