Technician A says that a relay piston in a foot valve responds to pneumatic signal from the primary section of the valve,by metering out into the secondary circuit the same pressure that acts on it.Technician B says that the further a primary piston travels through its stroke in a dual circuit foot valve,the more pressure is applied in opposition to foot pressure.Who is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. Technician A describes the function of a relay piston in a foot valve accurately, as it does respond to pneumatic signals from the primary section and meters out the same pressure into the secondary circuit. Technician B correctly explains the operation of a dual circuit foot valve, where the travel of the primary piston through its stroke increases the pressure in opposition to foot pressure, which is a fundamental aspect of how dual circuit foot valves modulate braking force.

Technician a Says That a Relay Piston in a Foot