Breakaway Valve > Tb - Aus4w-50 Break-away Valve

Document Title:

Technical Bulletin

Description:

Installation of the AUS4W-50 Break-Away Valve

Revision No: Issue Date:

1 06/01

The purpose of this technical bulletin is to outline the correct procedure for installing a Banlaw break-away valve. Also detailed are the forces required to separate the AUS4W50 valve, along with precautions that must be considered when locating the valve with respect to the orientation of the hose during a drive-away. The Banlaw break-away valve was designed to provide a means of both protecting refuelling system components from damage and preventing spillage of fuel in the event of a vehicle drive-away. The three shear studs connecting each half of the valve are designed to fracture at a certain stress, allowing the valve assembly to separate into 2 separate dry-break components. These dry-break components prevent fuel spillage from either the delivery hose attached to the offending vehicle or the remainder of the pipework downstream of the pump.

Figure 1: Function of dry-break operation The position of the valve with respect to the orientation of the hose during a drive-away greatly affects the force required to fracture the shear studs, hence allowing the valve assembly to separate. The tensile (axial) force required to separate the valve is 27kN (2.7 tonnes), whereas the required bending torque is only 1080Nm when the force is applied perpendicular to the valve axis. To ensure this correct mode of break-away, the valve should be mounted vertically at a height marginally above the level of the nozzle when connected to the vehicle.

Figure 2: Modes of valve separation and the corresponding forces Technical Bulletin – AUS4W-50 Break-away Valve 06/01

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Installation Notes: 1. To prevent premature failure of valve, take care not to apply excessive stress to studs when installing valve to pipework: (a) install one end of valve to fixed pipework, whilst applying torque only to that same end of valve assembly i.e. hold end securely with stilsons or similar when fixing pipe (b) secure valve to structure as in note 4 (c) install free end of valve to flexible hose leading directly to the refuelling nozzle, whilst applying torque only to that same end of valve assembly i.e. hold end securely with stilsons or similar when fixing hose tail 2. Install break-away valve vertically or otherwise perpendicular to axis of hose encountered during a drive-away. Location should be at a height marginally above that of the nozzle when connected to a vehicle. 3. To minimise risk of personal injury, it is recommended the valve should not be installed above head height 4. Ensure “upstream” half of valve is securely mounted to a structure capable of withstanding the force required to separate valve assembly. The “downstream” valve half is connected directly to the hose leading to the refuelling nozzle – see Figure 3. NOTE: The valve is non-directional with respect to orientation of flow through valve. Valve Repair: 1. Replace broken shear studs only with correct Banlaw replacement parts supplied in AUS4W-KIT. Installing parts other than genuine Banlaw parts will jeopardise the protection provided by the valve. 2. Care must be taken to ensure the o-ring is seated properly, and that no contamination or damage to the seat will affect its proper sealing 3. Tighten replacement shear studs to a torque of 2Nm only. Excessive torque will damage the studs, leading to premature stud failure.

Figure 3: Installation of the valve. TECHNICAL DATA: Hydrostatic Safe Working Pressure of Valve: 2,000kPa (290psi) Hydrostatic Burst Pressure of Valve: 8,000kPa (1160psi) Maximum Recommended Flowrate: 800LPM (211GPM) – diesoline fuel Technical advice on the installation and operation of quick-fill equipment is available from Banlaw head office or an authorised Banlaw distributor. Technical Bulletin – AUS4W-50 Break-away Valve 06/01

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