| SIZE OF PUMP. | DIAMETER OF WASTE PIPE FROM CONE. |
|---|---|
| 500-gallon. | 5 inches. |
| 750 „ | 6 „ |
| 1,000 „ | 7 „ |
| 1,500 „ | 8 „ |
The waste pipe can pass down to floor between the yokes at middle of pump. It should be piped in such a way that steam and gases from other drains or waste pipes will not work back through it, and, by being troublesome in the pump room, suggest the covering of the cone in any way, as it is desirable that the pump operator should always be able to see instantly any waste from the relief valve or air vent.
This cast-iron cone, connected to the safety valve and air vent, is included in price of pump, but the waste pipe beyond it is not.
45. Air Valve.
Fig. 13.
a. An air vent with a brass gate valve and brass pipe for connecting up, must be provided and connected with delivery elbow and discharge cone.
b. The size of this air vent should be one inch for 500-gallon and 750-gallon pumps, and one and one-fourth inches for the 1000-gallon and 1500-gallon sizes.
c. The hand wheel of this valve must be marked as per [Fig. 13]. The lettering must be very open, clear and distinct, not liable to be obstructed by grease and dirt, and of a permanent character.
The object of this valve is to reduce the pressure above force valves and secure a prompt riddance of all air that may come through the water cylinders when first starting up.