R-100
BALANCED PISTON FIRST STAGE REGULATOR
INSPECTION TECHNIQUES AND TROUBLESHOOTING
SECTION IV
4.0
INSPECTION TECHNIQUES
We encourage the service technician to develop good habits and practice in
inspection techniques during service and overhaul. Observing the exterior
condition of a regulator can offer clues on what may be found during overhaul.
Finding sand or salt deposits on the exterior crevices between mating parts may
indicate a regulator that is not properly maintained by the customer. One may
almost certainly discover more sand or salt deposits inside the second stage
case. In severe instances, a major overhaul and adjustment would probably take
less time to accomplish than to attempt a light cleanup leading to marginal
performance adjustment. Severe dings in the chrome plated brass body of the
first stage or plastic case of the second stage may indicate gross negligence in
handling the regulator. Further examination must proceed especially looking for
small cracks or damage in the second stage body, LP hoses, yoke knobs etc. It is
most important to look for cracks or damage near the external nut of the demand
housing in the second stage case. Mishandling may lead to severe stress
imparted into the LP hose resulting in cracks. Please refer to disassembly of the
stages for further discussion.
(A)
O-RINGS
O-rings are common off-the-shelf well-engineered reliable sealing devices. A few
words about handling them are required. O-rings can be ordered in different
sizes, rubber compounds and hardness (durometer). It is important not to
substitute o-rings from other sources in replacing TUSA regulator seals. Use only
factory supplied o-rings. As part of the TUSA annual servicing policy it is
recommended that all o-rings be replaced to maintain warranty. Further details
are available from the factory distributor. Do not attempt to clean or lubricate o-
rings outside of the recommendations in Section 5.1.
(B)
SEALING SURFACES
All metal parts use in TUSA regulators are made of either a corrosion resistant
stainless steel or chrome plated brass. Handle all metal components with care to
avoid scratches, dings or dents. Some components such as the first stage piston
in the R-100 have a very smooth and polished surface on the stem. This is the
sealing surface for the HP o-ring. A very unnoticeable scratch or ding on this
surface may allow a high-pressure leak across the o-ring. The piston cannot be
repaired and thus becomes an expensive replacement, which could have been
avoided by proper handling. Pay particular attention to the assembly of all
components and which surfaces are used for sealing against o-rings. Handle
these surfaces with particular care to avoid scratches, dings or dents.
Revised v1.0-2000
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