Regulation 11. Fittings-general provisions.

                                 P.U.(A) 5/70

FACTORIES AND MACHINERY (STEAM BOILER AND

                 UNFIRED PRESSURE VESSEL)

                         REGULATIONS, 1970

                    PART II - STEAM BOILERS

Regulation 11. Fittings-general provisions.

(1) All fittings for steam boilers shall comply with the following general provisions:

(i) cast iron shall not be used for-

(a) any fitting for service at a temperature greater than four hundred degrees

Fahrenheit or at a steam pressure greater than one hundred and fifty pounds per

square inch; or

(b) any blow-down fitting; or

(c)any feed valve or scum valve directly attached to the steam boiler shell for

service at a pressure greater than one hundred and fifty pounds per square inch;

(ii) bronze or gun-metal shall not be used for any fitting for service at a temperature

greater than four hundred and thirty-five degrees Fahrenheit;

(iii) the seat and valve head of every valve shall be made of metal resistant to corrosion

and no such seat shall be made of cast iron;

(iv) every valve of one and one-half inch bore and over directly fitted to a steam boiler

shell and every valve of two and one-half inch bore and over shall have its cover secured

by bolts or studs;

(v) every screw-down valve fitted with a screwed cover and directly connected to a steam

boiler shall be provided with a suitable cover locking device;

(vi) every valve for use with super-heated steam and valve of two and one-half inch bore

and over and every valve of one and one-half inch bore and over directly connected to

the steam boiler shell shall have an externally screwed spindle;

(vii) every valve having a separate valve seat shall have the same effectively secured;

(viii) every cock of one inch bore and over shall be packed with heat resisting material

and shall have special provision, other than the gland, for securing the plug;

(ix) the body of every fitting shall have been satisfactorily hydrostatically tested at the

manufacturer's or maker's works to a pressure not less than twice its design pressure;

and after assembly every fitting shall be satisfactorily hydrostatically tested to a pressure

not less than one and one-half times its design pressure;

(x) every fitting shall be secured to the steam boiler directly or indirectly, by a flanged

joint:

Provided that a screwed connection not greater than one inch nominal bore may be

provided for any steam boiler having a design pressure of one hundred and thirty pounds

per square inch or less, the screwed part of such fitting being an integral part thereof. In

such case not less than four full threads shall be engaged and where practicable a back

nut shall be fitted. Where the shell thickness is insufficient for this purpose a suitable pad

shall be provided.

(2) Where not otherwise provided in these regulations every steam boiler fitting shall be in

accordance with the provision of British Standard Specification No. 759-Valves and Gauges for

Land Boiler Installations.

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