TMV3 Thermostatic Mixing Valves

Thermostatic Mixing Valves for Healthcare Buildings

T&D are suppliers and stockist of thermostatic mixing valves which are TMV3 approved from Reliance Water Controls, Horne, Meynell & Dart Valley Systems.

The TMV3 approval scheme ensures thermostatic mixing valves comply with the NHS specification D08 and are therefore suitable for use within healthcare premises.

The TMV3 scheme was developed to ensure mixing valves were manufactured to handle the variations in UK water supply conditions such as low pressure from gravity fed systems or mixed pressure systems such as high pressure mains cold water and low pressure hot water supplies.

Additionally prior to when the NHS D08 specification was developed in 1997, UK regulations were significantly weaker and did not require TMV's to incorporate additional safety features needed within healthcare premises where users are at a higher risk of burns and scalds.

The TMV3 scheme is a third party scheme which is managed by BuildCert.TMV3 Approval Scheme for Thermostatic Mixing Valves

Buildcert & TMV3 Approvals

The TMV3 approval process is 5 year certification and is very strict and a large number of tests are carried out before approval can be given. Additionally manufacturers must comply with a number of other prerequisites before mixing valves can be considered for testing and approval.Buildcert Administer TMV3 Scheme Approvals

Manufacturers must hold ISO 9001 accreditation or be audited by BuildCert and they must subscriber to the BuildCert scheme. 

Manufacturers are required to submit 3 sample valves from a production batch of 30 for testing along with documents regarding the material specifications, drawings, installation and maintenance, marketing information and more.

All thermostatic mixing valves submitted must be WRAS approved or all non-metallic materials which are in contact with water must comply with WRAS requirements or comply with BS6920.WRAS Approvals are required for TMV3 Approval

Tests carried out include, amongst others:

  • Thermal element endurance tests
  • Hot spike test (Temperature overshoot on start up)
  • Temperature response on temperature adjustment
  • Thermal shut off
  • Temperature stability on changing pressures, inlet temperatures and on reduced flow rates

Finally, even after the thermostatic mixing valve has been awarded TMV3 approval, the valve must continue to be subject to performance tests at least twice over a period of 5 years.

TMV3 Thermostatic Mixing Valve from Reliance Water Controls

The scheme specifies that TMV3 approved thermostatic mixing valves must comply with the following maximum mixed water outlet temperatures and operating conditions:

TMV3 Thermostatic Mixing Valve Maximum Temperatures & Pressure Ranges
Designated Use Maximum Temperatures
Bath Filling 44ºC
Assisted Bathing 46ºC
Showers 41ºC
Bidets 38ºC
Operating Conditions High Pressure Low Pressure
Maximum Static Pressure 10 bar
Hot & Cold Flow Pressure Between 1.0 and 5.0 bar Between 0.2 and 1.0 bar
Hot Supply Temperature Between 52ºC and 65ºC
Cold Supply Temperature Between 5ºC and 20ºC

T&D can identify the TMV3 thermostatic mixing valve most suitable for your requirements and can offer competitive prices with next day deliveries available from stock.

Contact our technical sales engineers today to find the solution for your needs.

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TMV3 Thermostatic Mixing Valves

Heat Tracing - Thorne & Derrick