Installation Instructions
Pipe Cowl Product Range

Last Updated

November 17, 2021

Flowflex reserve the right to alter the product ranges and specifications associated with its products without prior notice

The Pipe Cowl is a pre-soldered solution for pressure relief termination. Traditional pressure relief terminations require extra tube, 2 bends and 4 soldered joint to be made resulting in a different finish each time. The pipe cowl has the advantage of guaranteeing a neat finish every time, with one soldered joint to make meaning installers save time and money. The pipe cowl also complies with all current legislation and NHBC approved.

The solder ring pipe cowl is ideal for domestic and commercial applications and is available in two sizes to enable fixes to both 15mm and 22mm copper tube which is manufactured to BS EN 1057. We are also delighted to introduce the new extended pipe cowl, with 300mm of 15mm copper tube. This enables the installer to carry out full installation from inside the building. This removes the need of spending time and money on scaffolding or abseiling allowing for easy high-level installation.


  • Domestic
  • Commercial



Soldered joints depend on capillary action drawing free-flowing molten solder into the gap between the fitting and the tube.

The selection of a solder depends primarily on the operating pressure and temperature of the system. Consideration should also be given to the stresses on joints caused by thermal expansion and contraction.

In the cases of a short run, or a long run with an expansion loop, the stresses caused by a temperature change are usually insignificant.

The 50:50 tin:lead solder is suitable for moderate pressures and temperatures. For higher pressures, or where greater joint strength is required, 95:5 tin:silver can be used. When operating outside of these parameters, please consult us before installation.


The functions of soldering flux are to protect against re-oxidation of the joint during the soldering procedure, promote wetting that allows capillary action to begin, and to assist in residual oxide removal.

Flux should only be applied to surfaces that have been cleaned using an abrasive cloth. After this, only enough flux to lightly coat the areas should be used, only in the areas where the tube and fitting will overlap. All fluxes should be used sparingly and strictly in accordance with the manufacturer's instructions. The use of excessive flux must be avoided. Some fluxes are more aggressive than others but all fluxes should be considered to be corrosive to some extent.

An oxide film may re-form quickly on copper after it has been cleaned. Therefore, the flux should be applied as quickly as possible after cleaning.


  • Copper Pipe
  • Pipe Cowl
  • Flux
  • Flame
  • Hand & Eye Protection


Check Pipe Cowl and Tube

Check Pipe Cowl and Tube

Ensure that you have enough copper pipe to reach the pipe stop in the pipe cowl and that you still have space for the cowl to sit flush to the wall.

Only one soldered joint to make.

Add Flux and heat

Add Flux and heat

Simply add some flux to the pipe cowl and apply heat to create a seal.

Do not over flux.

Extended Pipe Cowl

Extended Pipe Cowl

Extended Pipe Cowl can be installed from the inside of the building. Simply push the cowl through a pre drilled hole. Pull back the cowl to sit flush to the wall. Cut & connect the copper pipe accordingly.

Extended Pipe Cowl is self sealing meaning full installation can take place inside the building.


We recommend that all systems are throughly tested upon completion. Whenever possible, completed systems should also be flushed to remove debris.

Hydraulic Installations

In hydraulic based installations, the system may be tested to 1.5 times the working pressure of the system. If higher test pressures are required, then please contact us for further advice.

Any Questions?

Our team is available for you anytime.