Armitage Shanks Markwik 21 - Water Supply Conditions; Water Supply Conditions Introduction; Supply Pressure Requirements; Healthcare Establishment Conditions

4
In accordance with the NHS model engineering specications DO8 this valve has approval for
the following applications:-
High Pressure HP- -WE
Low Pressure LP- -WE
For this type of application the following supply conditions must apply:
Operating pressure range: High Pressure Low Pressure
Maximum static pressure 10 bar 10 bar
Flow pressure hot and cold 1 to 5.0 bar 0.2 to 1.0 bar
Hot supply temperature 55 to 65 °C 55 to 65 °C
Cold supply temperature 5 to 20 °C 5 to 20 °C
4.3 Healthcare Establishments
Note:
Fittings operating outside these
conditions cannot be guaranteed
by the scheme to operate as TMV3.
*52°C absolute minimum can
be used but not recommended
Table 1 Supply conditions for healthcare establishments
Effectively this means:
Differential between HOT and COLD inlet temperatures ( ∆t ) must be 32C° min and 60C° max
Differential between HOT inlet temperature and MIXED temperature ( ∆t ) must be 11C° absolute mini-
mum but > 14C° preferred
See 9.3 Audit checks on TMV’s.
4.1 Introduction
4.2 Supply Pressure Requirements
This proximity operated thermostatically controlled mixers are manufactured to the highest standards
and have approval to TMV3 which permits it to be installed in healthcare establishments such as hospi-
tals, nursing homes and residential care homes. When installed in healthcare establishments the supply
conditions detailed in Table 1 must be observed and the commissioning and servicing requirements
detailed on section 9 & 10 must be followed.
For other installations this is not a requirement.
This mixers are designed to be installed on all types of plumbing systems.
Hot and cold water supply pressures should be reasonably balanced, however, the mixer will function
within specication on unequal pressures up to 5 :1.
The mixers has integral isolating valves which permit servicing of the strainer, ow regulator & thermo-
static cartridge. They are also used for thermal disinfection.
The minimum pressure for the correct thermal operation is 0.2 bar. However, in order to achieve an ac-
ceptable ow performance at very low pressures it may be necessary to remove the ow regulators (10).
IMPORTANT: DO NOT REMOVE check valves tted inside the inlet tails (19) - see gure 27.
4 WATER SUPPLY CONDITIONS