Pressure limiting valve, component description

B14.40-0098-06

Provision

Represented in model 382.154

9 Pressure limiting valve with quick discharge (33.03)

10 Compressed air operating unit

The pressure limiting valve (9) is part of the compressed air (10) operating unit and is located inside it, to the right of the chassis grid near the tail pipe with a catalyst.

Task

The pressure limiting valve (9) reduces the compressed air flow pressure to a pre-established value of 5.5 bar.

B14.40-0170-03

Composition

1 Pressure spring

2 Intake

3 Piston

4 Piston

5 Exhaust

6 Valve

7 Valve

8 Housing

A Supply connection

B Low air pressure operation connection

C Vent

D Compressed air chamber

E Hole

F Compressed air chamber

G Compressed air chamber

Function

The pressure limiting valve (9) is adjusted so that only a predetermined pressure can be transferred to the connection (B). The pressure spring (1) actuates constantly on the pistons (3) and (4). This way, the piston (3) is kept in its resting position against the case (8). The intake (2) is open. The air that enter in the supply connection (A) flows from the compressed air chamber (F) to the compressed air chamber (G) and reaches the connected devices through the connection (B).

The pressured built up in the compressed air chamber (G) overtakes the pressure spring (1) power and moves the piston (3) and (4) downwards. The valve (7) closes the intake (2) and reaches its final position. Due to the air consumption at the low pressure side, the pressure balance on the piston (3) is canceled. The pressure spring (1) presses the piston (3) and (4) upwards again. The intake (2) opens, the air reaches the predefined pressure and the balance is established.

If pressure on the connection low pressure side (B) overrun the expected value, the piston (3) actuates as a safety valve and opens the output (5). The exceeding pressure will bleed from the breather (C) to the outside.

If the pressure in the compressed air chamber (F) reduces the pressure in the compressed air chamber (G), the valve (6) opens. The chamber compressed air (G) flows, at this moment, back to the connection (A), through the hole (E) until the opening of the intake again (2) due to the actuation of the pressure spring (1). There is a pressure balance between connections (B) and (A).