Hep20 Technical Handbook

Hep 2
O ® General Considerations
Pressure Testing
Installers should ensure that all non-
Hep 2 O ® products can withstand
the test pressure by checking with
other relevant manufacturers.
When testing Hep 2 O ® pipework
systems, the recommended test
pressure is:
• for Hep 2 O® fittings with grab
wedges – 1.5 times working
pressure.
• for Hep 2 O® grab ring and
SlimLine fittings – a further test
to 18 Bar.
If the system contains any grab ring
or SlimLine fittings the further test
to a maximum of 18 Bar should
always be undertaken.
Care should be taken to disconnect
any appliances or fittings that will
not withstand, or will be damaged
by, testing at 18 Bar.
Gauge
Valve 1
Valve 2
Figure 32
Hep 2 O ® Pressure Testing Kit (HX81)
Setting up the pressure test
The testing procedure is set out
below. The duration of the test
should be not less than 1 hour in
accordance with BS 6700.
Pressure test procedure:
1. Ensure that any non-Hep 2 O ®
components in system will
withstand test pressure.
2. Blank off all open ends using
Hep 2 O ® Blanking Pegs (HX44)
or Blanking Plugs (HX41).
3. Connect pressure hose to
system at a convenient point
using a demountable socket.
4. Close Valve V2 and open Valve V1.
5. Fill system to be tested with
water ensuring that the system
is completely full of water
(purge all air).
6. Raise pressure to test pressure
and close Valve V1.
7. At end of test duration, gently
tap gauge with a finger (to
ensure pointer is ‘free’). Read
pressure on gauge. No
appreciable drop in pressure
should be noticed to indicate
the system is watertight.
8. Release Valve V1 and V2 to
release pressure from system.
Drain system if necessary.
9. Replace cap and components in
socket used for connection to
test kit.
10. Re-connect non-Hep 2 O ® parts
of the system.
It is important that this pressure
testing procedure is not used as a
substitute for making sure the
correct insertion depth of the pipe is
made into the fitting. The chevron
marks on the pipe or a measured
pencil mark should always be used.
See page 6 for the correct method
of connecting pipes to fittings.
Painting Hep 2 O ®
Hep 2 O ® can be painted where this
is felt to be necessary, e.g. outdoors
to protect the pipe from sunlight
and the effects of ultra violet light.
It is preferable when painting
Hep 2 O ® to use emulsion paint.
However, oil based gloss paint can
be used in conjunction with
undercoat. Cellulose based paints,
paint strippers or thinners should
not be used.
Before painting, ensure all surfaces
are clean, free of grease and dry.
Freezing for Maintenance
and System Modification
Hep 2 O ® pipe can be frozen for
maintenance or repairs without
damage to the system. Freezing
equipment manufacturers
instructions should be followed.
Freeze at a reasonable distance
from where pipe is to be cut.
Antifreeze
Antifreezes based on Ethylene Glycol
mixtures will not have an adverse
effect on Hep 2 O ® . However if there
is any doubt as to their suitability
please contact the Hepworth
Plumbing Products Technical Advisory
Service for advice.
Woodworm/Timber
Treatment
When treating timber for
woodworm or timber rot, waterbased
solutions are generally
accepted. But care should be taken
to protect and cover Hep 2 O ® pipe
and fittings prior to any spraying.
It is preferable to carry out any
spraying prior to Hep 2 O ®
installation.
Solvent based treatments should
not be used.
For further information contact the
Hepworth Plumbing Products
Technical Advisory Service.
82