Even threads direct into backhead copper plates? I thought that was a complete no-no these days.
Nothing here that precludes that arrangement.
Examination – Non-Commercially Built New Boilers
7.1 During construction of a new boiler the following items, where
applicable, shall be taken in to consideration by the Inspector to
determine, as far as reasonably practical, that the boiler is sound.
a. Owing to the ductility of annealed copper in a newly
constructed boiler some minor distortion/bulging may take
place and this should be allowed for.
b. Screw threads in mounting bushes might be burnt or scorched.
Check that screw threads of fittings and their mounts are of
adequate depth to maintain sufficient strength.
c. Check that copper fireboxes with girder stay arrangements
have adequate penetration of silver solder to all joints.
d. Check that hollow stays (e.g. for blower) that are fitted by
mechanical means have adequate strength and integrity of
joints.
e. Butt strap joints in copper boiler barrels shall be examined to
indicate that full penetration of silver solder has been achieved
before other jointing is progressed.
f. In silver soldered copper boilers check that there has been
sufficient heat penetration to produce an adequate joint around
all stays.
g. Check that the faces of mounts for water gauges remain
parallel to one another during construction so that no undue
stress is applied to the tube glass on assembly.
h. Check that there is no collapse of fire tubes or super heater
flues.
i. For welded boilers the Inspector may request to examine the
preparation of joints before welding. Checks may also be made
during construction for distortion that may occur during the
welding process.
This is a VERY important statement...
3.9.c.
The individual should know his own limitations and should not
act outside his level of qualification or knowledge.
