Cast Iron SimpleFIT Drainage System: A video guide to pre-relaxation of the rubber gasket prior to assembly

The SimpleFIT drainage system, made from quality cast iron, is ideal for traditional style, heritage or listed properties. But its clever, simple push-fit method of assembling the components significantly reduces installation time and, therefore, cost.

That said, to aid insertion of the SimpleFIT pipes into the eared or non-eared sockets, pre-relaxation of the rubber gasket inside the sockets immediately prior to assembling the joint is essential.
A PDF installation guide has always been available on our downloads web page

But a short video demonstration always makes an explanation clearer than just words and still pictures, so we put one together for you below.

Video transcript:

  • To aid insertion of the components immediately prior to assembling the joint
    You will need:
    1. The relaxing tool
    2. The lubricant
    3. And the eared/non-eared socket with the logo up-side-down
  • Apply lubricant to the rubber gasket inside the eared/non-eared socket
  • Apply lubricant to the open end of the relaxing tool
  • Insert the relaxing tool into the socket
  • Slide it up and down over the gasket sealing face three or four times
  • The gasket will now be temporarily softer and enable easier assembly
  • Add a small amount of lubricant to the pipe/fitting
  • Turn the pipe/fitting over and insert into the socket

Additional Information:

  • The same process will need to be repeated for the other side of the socket before the next length of stack/fitting can be inserted.
  • Using at least one eared socket on each fitting will enable the system to be anchored securely to the building.
  • Installation should be from the bottom to the top of the soil stack with, typically, a length of pipe, boss pipe or branch at the base of the stack.
  • The first pipe, boss pipe or branch should be connected to the underground drainage system and have an eared socket fitted to its top to ensure a secure base and stability of the pipework before proceeding further.
  • Subsequent pipes/fittings installed vertically above this point should incorporate at least one eared socket.
  • On branch ‘arms’ (i.e. off the vertical) we recommend the use of a plain socket to provide the correct aesthetic.

If you have any other questions about the SimpleFIT Drainage System, or any other Rainclear range, get in touch by phone on 0800 644 44 26 or email

Download the PDF Installation Guide
Browse & Buy Cast Iron SimpleFIT

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