Plumbing Connection 4-2015

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4 0 PLUMBING CONNECTION SUMMER 2015
WHAT NEEDS TO BE AMENDED?
The Standard AS/NZS 3500 parts 1 and 4 need amending
to meet current contemporary practices to include or
reference press-fit as a valid and accepted method of
installing pipework, specifically stainless steel. Press-fit is
already an accepted method of jointing in AS 3688 and has
been for over 10 years. The two standards just need to be
linked.
Standards Australia currently view this matter as a
technical change – and not a simple correction amendment
– as proposed by the industry. Until the Standard is
amended to include the accepted practice of press-fit
connections, these products need to be approved using
‘alternative solutions’.
The following is the proposed amendment the industry
put forward to Standards Australia that rectifies the lacking
acknowledgment of press-fit as an acceptable method of
jointing:
2.4.2 Metallic pipes and fittings
Metallic pipes and fittings shall comply with the following:
a) Fittings used in conjunction with Stainless steel (SS) shall be
either copper alloy compression type and be dezincification
resistant (DR) or SS capillary type manufactured from grade
304 or 316 complying with ASTM A268/268M or mechanical
jointing end connectors complying with AS 3688.
4.4.9 Jointing of stainless steel pipe and fittings
4.3.8.2 Jointing of pipes larger than DN 25
Joints in stainless steel piping larger than DN 25 shall be either–
a) Butt welded using a tungsten inert gas (TOG) argon arc
method and–
(i) have a gap not greater than 0.5 mm between the
abutting pipe ends to be joined;
(ii) have inserted a back-up ring 6 mm long, made from
the parent, to straddle the joint of pipes with a wall
thickness less than 1.2 mm;
(iii) use a low carbon stainless steel type filler rod not
greater than 2 mm in diameter; and
(iv) be tack-welded in not less than four spots around the
circumference, prior to welding the entire joint; or
b) have flagged joints, fabricated by rolling or welding to the
pipe, a stub flange of the same wall thickness as the pipe,
having a diameter conforming to dimension ‘F’ in AS 2129 or
AS/NZ2 4331, with mild steel backup flange complying with
AS 2129 or AS/NZS 4331 fitted, and a gasket not less than 3
mm thick inserted; or
c) mechanical jointing end connectors complying with AS
3688.
ALTERNATIVE SOLUTIONS
PROPOSED AMENDMENT TO AS/NZS 3500.4, SECTION 2:
PROPOSED AMENDMENT TO AS/NZS 3500.4, SECTION 4:
This is not an official document of Standards Australia.
This is not an official document of Standards Australia.
Stainless steel crimp fittings have been used to great effect
for over 50 years, yet Standards don’t cover the material.
WHAT YOU NEED TO DO?
Aside from the fact that the wheels of progress move
slowly across the plumbing sector, there is a very real threat
to your business if you don’t apply for an alternate solution
with your local regulator to cover the past/continued use of
these stainless steel press-fit connections.
It’s rather ironic that at a time when government at all
levels say they are committed to reducing red tape; again
more complexity is upon small business to comply with
practices already approved and installed for years.
Given this issue was still being worked through by a
number of parties as we went to press with this edition
of Plumbing Connection , the current solution for both
specifiers and installers is not clear. We’ll be following this
situation closely with updates published on our website
in due course.