Size of Pipe ×
Diam.
of Flange.		Diameter
of
Bolt Circle.		Number
of
Bolts.		Size
of
Bolts.		Flange
Thickness
at Edge.
Inches.Inches. Inches.Inches.
3× 71⁄2 6 45⁄8×21⁄213⁄16
31⁄2× 81⁄2 7 45⁄8×21⁄27⁄8
4× 9 71⁄2 43⁄4×23⁄415⁄16
41⁄2× 91⁄4 73⁄4 83⁄4×315⁄16
5×10 81⁄2 83⁄4 ×315⁄16
6×11 91⁄2 83⁄4×31
7×121⁄2103⁄4 83⁄4×31⁄411⁄16
8×131⁄2113⁄4 83⁄4×31⁄21⁄8
9×15131⁄4123⁄4×31⁄211⁄8
10×16141⁄4127⁄8×35⁄813⁄16
12×1917127⁄8×33⁄411⁄4
14×21183⁄412 1×41⁄413⁄8

Do not drill bolt holes on center line, but symmetrically each side of it.

On steam and exhaust openings loose flanges threaded for wrought-iron pipe must be provided.

Where the situation will not permit of a standard flange on exhaust opening for lack of room, a special flange threaded to fit the proper size wrought-iron pipe may be used.

40. Air and Vacuum Chambers.

a. Air and vacuum chambers in accordance with the sizes given in the following table must be provided with all pumps. If the air chamber is cast iron, the pump manufacturers must warrant that it has been subjected to a hydraulic test of 400 lbs. per square inch before it is connected to pump.

It is to be thoroughly painted inside and out to diminish its porosity.

SIZE OF VACUUM AND AIR CHAMBERS.

Vacuum Chamber is
to contain:—		Air Chamber is
to contain:—
500-gallon pump.13 gallons.17 gallons.
750 „ „18 „25 „
1,000 „ „24 „30 „
1,500 „ „30 „40 „