s

Service information

Fuel check valves (RSV)

si 0044 GB

for various applications

VHH 06.99

Vehicle :

Product :

Various vehicles and applications

Check valves

Check valves are used in vehicles for various purposes. They are used as standard especially in fuel systems, e.g. to prevent tank or line discharge.

The valves can easily be retrofitted and are therefore ideal as a solution to both vehicle use as well as other application. For retrofitting purposes, the valves listed below are recommended. Application information can be found in the table overleaf.

Ø7

Ø18

Ø6

Ø9 Ø6

20

61,5

20

2,5 P10021/0

2,5

20

Ø8

4 P10021/0

Ø4 Ø6

20

Ø8

62

Ø18

2,5

4

2,5

Ø4

Ø7

Fig. 1

Ø6 Ø9

Fig. 2

Reg. Nr. 4/4 00-161.4-GB

Information on installation: The arrows on the housing (arrow, Fig. 2) indicate the direction of flow. Pierburg-No. Connection Opening pressure Counter-pressure 1) Permissible leakage Bursting pressure Figure 1) 2)

7.20469.51.0 Ø6 mm 10 -15 mbar max. 0,8 bar none 5 bar 2) 1

7.20234.50.0 Ø8 mm 10 -15 mbar max. 2,0 bar -0,3Ø 5 bar 2) 2

7.20234.52.0 Ø8 mm 10 -15 mbar max. 0,8 bar none 5 bar 2) 2

Counter-pressure is the pressure that may be applied to the valve in closing direction Pressure applied to both connections simultaneously

Subject to change of illustrations and text.

MSI Motor Service International GmbH • D-41456 Neuss • Phone (02131) 520-0 • Fax (02131) 520-663 • E-Mail: [email protected] - A Company of Kolbenschmidt Pierburg AG -

Fuel supply

PIERBURG

Fig. 3 Fuel supply for carburettor engine 1 Tank 2 Mechanical fuel pump 3 Check valves (2) 4 Fuel vapour separator

4 3

2 1

Fig. 4 Fuel supply for carburettor engine 1 Tank 2 Electric fuel pump, type E1F 3 Check valves (2) 4 Mechanical fuel pump (deactivated)

3

2 4 1

Fig. 5 Fuel supply for carburettor engine 1 Tank 2 Electric fuel pumps, type E1F as pump assembly 3 Check valves (3)

3

2 1

Fig. 6 Fuel supply for diesel engine 1 Tank 2 Mechanical fuel pump 3 Check valve

3

1

2

Recommendation for check valve retrofitting as a problem solution Carburettor engines Problem

Possible cause

Remedy/Measure

Remark

Long starting times after extended period of nonuse.

No fuel in suction line, mechanical fuel pump must fill at start of speed.

- For mechanical fuel pump, place check valve at tank outlet in suction line. - For electric fuel pump, place the check valve downstream in flow line behind the pump.

Mechanical fuel pump, Fig. 3

Electric fuel pump, Fig. 4

Motor starts badly, floods when vehicle parked on incline.

Fuel has flowed via return line and open float needle valve into carburettor and suction line.

- Place check valve near the carburettor in return line.

Fig. 3

Lengthy starting times /

For systems with two pumps connected in parallel, part of the flow is circulated through the second pump. The flow line is also emptied of fuel when the pumps are stopped.

- Place check valve downstream in flow line behind each pump.

Particularly when only one pump operates, Fig. 5 Observe counterpressure. In case of higher pressure, use valves 7.20234.00.0

Problem

Possible cause

Remedy/Measure

Remark

Engine starts badly after extended periods of nonuse.

Air in fuel system (flow line).

- Place check valve in suction pipe directly at tank outlet. - Check system for leaks.

For both mechanical and electric priming feed pump, Fig. 6

lack of performance

Diesel engines

Check valve, information on various applications Decanting systems and additional tanks Problem

Possible causes

Remedy/Measure

- Delayed pumping: Premature pump wear due to air in lines. - Long lines (risk)

Lines run empty when pump is stopped.

Place check valve directly at extraction point in suction line. For long lines, position second check valve downstream behind pump in pressure line.

Pump assembly (for increasing flow rate or for safety) - Insufficient pump capacity - Delayed delivery

In the event of failure or stoppage of a pump, part of the flow is circulated through the second pump.

Place a check valve downstream behind each pump in flow line, Fig. 7. Observe counter-pressure. In case of higher pressure, use check valve 7.20234.00.0

Fig. 7 Fuel system with additional tank 1 Additional tank 2 Electric fuel pumps, type E1F as pump assembly 3 Check valves (three) 4 Operating tank

1

3

2

3

4

Fig. 8 Decanting station 1 Tank 2 Electric fuel pump, type diverse 3 Check valve

1

3

2