Fig. 3.
This style of cushion port makes the pump safer in case cushion valves are unskillfully left open too wide and tends to prevent a pump from pounding itself to pieces in case of a sudden release of load, as by a break in suction or delivery mains, or by a temporary admission of air to suction pipe.
Fig. 4.
Pumps made with this form of cushion release, have given very satisfactory results, and if the ports are properly located, there will be no re-bound of piston.
c. Cushion valves must be always provided with hand-wheels marked as per sketch, for the reason that very few men in charge of fire-pumps are found to clearly understand or to remember their use.
The lettering must be very open, clear and distinct, not liable to be obscured by grease and dirt, and of a permanent character.
It is desirable that spindle or wheel be so formed that a monkey wrench can get a grip to open a jammed valve. [Fig. 5] shows the stem flattened for this purpose.
