THE HONGKONG GOVERNMENT GAZETTE, DECEMBER 3, 1909. 993
(21.) The working pressure of well made copper pipes, when the joints are brazed, is found by the following formula :----
6,000 × (T — 1'6)—W
When the pipes are solid drawn and not over 10" diameter, substitute in the foregoing formula for ye
16.
The working pressure of wrought iron pipes made of good material and lap welded, provided that the minimum thickness is not less than inch :--
6,000 × T D
W
The working pressure for cast-iron pipes:-
3,500 × (T — 1 ) ____
-
W
D
In all the above cases :-
W-working pressure.
T-thickness in inches.
D-internal diameter in inches.
(22.) All new steam pipes must be tested by hydraulic pressure to twice the working pressure.
(23.) All steam pipes must be fitted with an efficient drain cock and pipe at their lowest parts.
Form A.
district
Register of boilers and engines at work within the limits of the
under Ordinance No. of 1909, to be revised every twelve months.
Name of Owner and
Index Numbers of Boilers and Prime
Movers.
Description.
Number of Boilers at Work.
Boilers.
Prime Movers.
Date of Ordinary
Remarks.
Date of Thorough Examination. Examination.
Page 10Page 11
General.
Index No. of Firm.
Form B.
Dimensions of Boiler.
Date of Inspection.
Feed
Combustion Chamber.
Internal Flues.
Apparatus.
Appara- Blow out
Pres-
Gauges. Water
sure
tus.
Gauges.
Name and Address.
Shell.
Furnaces.
994