Mechanical maintenance

We conduct a full range of mechanical maintenance across the gas pipeline network, using specialist repair techniques that often eliminate the need for expensive valve replacements. We can usually repair valves without decommissioning the pipeline.

Our expertise includes:

  • flushing and sealing techniques using existing valve connections
  • sealant-vent plug adaption carried out where bling plugs are fitted
  • vent-sealant line replacement
  • repair and replacement of actuators and extension tubes
  • stem-seal leak repairs
  • revalidation and pressure testing on site
  • ball-valve maintenance or replacement
  • gearbox repair and maintenance
  • plug-valve maintenance or replacement.


Ball valve maintenance and replacement

We regularly receive calls regarding faulty ball vales, Our expertise enable us to determine whether there is an issue with the ball valve or the gearbox/actuator operation system. 

Gearbox repair and maintenance

We have extensive knowledge of the different types of gearboxes. We are able to source replacement parts and seals. We can then return the gearbox or actuators back to full service. 

Plug valve maintenance and replacement

At PMC we have extensive knowledge of the different types of plug valve and gearbox and actuators.

Repair and Replacement of Actuators and Extension Tubes

We can repair and replace actuaries and extension tubes. We can bring below ground valves to a easy operational height along with other services such sealant and vent lines above ground, removing the need to enter valve pits. 

Re-Validation and Pressure Testing of Valves

If the valves can be removed from the service they can be returned to our depot in Ambergate to undertake a full sweep of maintenance: i.e flushing procedure, gearbox maintenance/overall maintenance, if required. New sealant and vent valves can be fitted, along with a full pressure test to National Grid valve test v6 standard.

Sealant and vent plug adaption

Sealant and vent plug adaption turns the existing plug (which can be of various sizes) into the nipple with a pressure drill. We can then input grease into the valve thus providing a seal. 

The vent line is adapting the plug to fit a valve so we can then vent the cavity proving the seal. 

Stem seal leak repairs

To fix stem seal leak repairs we have invented the lapping tool. For more information on this click here.  We also work on the full range of makes and models used across the network.

Valve Flushing and Sealing Techniques

We use a range of different products and techniques to achieve seals on valves. We know the correct flush product and sealant technique for each different make and model of valve. 

Vent and sealant line replacement

We can undertaken replacement of vent and sealant lines on any make or model of valves - ether live or de-pressurised.