BS 7942:2011

This standard BS 7942:2011 Thermostatic mixing valves for use in care establishments. Requirements and test methods is classified in these ICS categories:

• 91.140.70 Sanitary installations

This British Standard specifies performance and material requirements and gives test methods for three types of TMV, of nominal size up to and including DN25, for use in care establishments. The TMVs covered by this standard are those which are suitable for the hot and cold water supply pressures and temperatures given in Table 1, and those which are suitable for the applications given in Table 2.

Annex A to Annex E give the apparatus and test methods for the durability of TMVs, Annex F to Annex M and Annex O to Annex S give the apparatus and test methods for the performance of TMVs. Annex N gives an assessment of transient values, Annex T gives a summary of thermal performance requirements and Annex U and Annex V give recommendations for commissioning and in-service tests.

Table 1 TMV general use conditions

Pressure/temperature range	High pressure (HP)	Low pressure (LP)
Operating pressure
Maximum static water pressure (MPa)	1.0	1.0
Flow pressure, hot and cold (MPa)	0.1 to 0.5	0.02 to 0.1
Operating temperature
Hot supply temperature (°C)	55 to 65	55 to 65
Cold supply temperature (°C)	5 to 20	5 to 20

Table 2 Mixed-water temperature

Application	Designation A)	Mixed-water temperature (at point of discharge) °C max.
Bidet	HP-B, BE; LP-B, BE	38
Shower	HP-S, SE; LP-S, SE	41
Washbasin	HP-W, WE; LP-W, WE	41
Bath (44 °C fill)	HP-T44; LP-T44	44
Bath (46 °C fill)	HP-T46; LP-T46	46
Bath and shower mixer (44 °C bath fill)	HP-D44; LP-D44	41 (shower);
		44 (bath)
Bath and shower mixer (46 °C bath fill)	HP-D46; LP-D46	41 (shower);
		46 (bath)
NOTE For washbasins, washing is assumed to take place under running water. A) A TMV with a diverter designation (D) has the capability to change and control the mixed-water outlet temperature in line with the temperatures defined above when the supply path is changed from bath to shower or shower to bath.