Technical Bulletin � Nozzle Shut-Off Mechanism 07/01 �The Refuelling Specialists�

Document Title: Technical Bulletin Revision No: 1Description: Mechanics of the AutomaticShut-Off Mechanism for BanlawRefuelling NozzlesIssue Date: 07/01

The objective of this technical bulletin is to briefly detail key information on themechanics of the automatic shut-off mechanism for Banlaw refuelling nozzlesPrinciples of the Automatic Shut-Off MechanismThe automatic shut-off mechanism of the Banlaw refuelling nozzle operates on theprinciple of detecting static (wall) pressure of the fluid flow through the nozzle. Asample of the mainstream fluid is transferred into the nozzle tube via a small orificeon the rear surface of the retainer. Thus a portion of the static pressure of themainstream fluid is also held within the tube. A small orifice at the other end of thetube allows the sample of fluid to flow into the rear piston chamber, at the forwardside of the piston. The nozzle will shut-off if the static pressure detected in the rearchamber is sufficient to overcome the force maintaining the nozzle in the ONposition. This being the resultant force of the receiver spring and nozzle back spring,and the fluid drag created by flow over the nozzle retainer and receiver poppet.The magnitude of static pressure at entry to the nozzle is a function of a number offactors, including the type of fluid being transferred, the flow-rate, and the level offlow restriction � head loss � both through the nozzle/receiver assembly anddownstream of the nozzle.

HEAD LOSS = FLOW RESTRICTION = PRESSURE DROPFigure 1.1 shows the constituent parts of the nozzle and their role in the shut-off ofthe nozzle. Note the increase in the static pressure at entry to the nozzle (P1) as theautomatic shut-off mechanism is initiated.Drawing (a) illustrates the status of the nozzle during normal flow conditions. Thestatic pressure P1(a) is less than the static pressure that initiates nozzle shut-off,hence the nozzle remains in the fully ON position.Drawing (b) illustrates the status of the nozzle once the automatic shut-offmechanism has been triggered. This has occurred since P1(b) has exceeded thestatic pressure that initiates nozzle shut-off, hence the nozzle will begin to turn OFF.P1(b) is not only increased by the rise in flow restriction due to tank pressurisation,or a closing valve etc, but also the increase in head loss across the nozzle outlet asboth the nozzle and receiver close.Drawing (c) shows the nozzle in the fully OFF position. The pump pressure iscontained within the nozzle, whilst the fluid pressure within the receiver, and hencethe delivery line into the tank, is allowed to decrease to a level governed only bystatic fluid head and atmospheric pressure.

Technical Bulletin � Nozzle Shut-Off Mechanism 07/01 �The Refuelling Specialists�

Figure 1.1: Automatic Shut-Off of Banlaw Refuelling NozzleFurther information on the operation of the Banlaw refuelling nozzle is available inthe Technical Bulletin on Nozzle Theory � available from August 2001.Disclaimer: The information supplied in this document is meant as a guide only.Banlaw Pipeline Pty Ltd accepts no liability for any damage or event resulting fromthe implementation of any content of this document. To confirm the correct advicehas been received, all details should be checked with an �Authorised Banlaw�distributor or Banlaw Pipeline direct prior to installation.

Technical Bulletin � Nozzle Shut-Off Mechanism 07/01 �The Refuelling Specialists�

Further technical advice on the installation and operation of Banlaw equipment isavailable from Banlaw head office or an authorised Banlaw distributor.BANLAW PIPELINE PTY LTD - CONTACTSTelephone: +61 (0)2 49714888Fax: +61 (0)2 49714910www.banlaw.comSALES & MARKETING PRODUCTION &QUALITY ASSURANCE FUELTRACK &ELECTRONICS ENGINEERING(MECHANICAL)Nick FORAN Paul BUCKTON John GREGORY Adam PEATTIEsales@banlaw.com.au paul@banlaw.com.au hoppy@banlaw.com.au adam@banlaw.com.auMob: 0408 497212 Mob: 0409 663072 Mob: 0408 492408

Principles of Banlaw system – 04/01

PRINCIPLES OF THE BANLAW PIPELINEQUICK-FILL DRY-BREAK REFUELLING SYSTEM

Figure 1: Overview of Banlaw System

The BANLAW Refuelling System uses both Dry-Break and Quick-Fill technology, producing anenvironmentally friendly and more efficient method of liquid refuelling. Problems associated with theconventional “splash-fill” method, such as spillage and foaming are eliminated, whilst additionaladvantages such as higher refuelling rates and alternative filling points make the Banlaw system abetter way to refuel your equipment.

A Banlaw nozzle has been designed for all existing refuelling systems found in the mining and railindustries. These include the BAM800, BAH800, BAR800, BAM1000, BAR1000, and the AUS45,catering for refuelling rate requirements between 120 and 1000L/min. Associated equipment such astank vents, drop-tubes, nozzle receivers and receiver shells are custom fitted to each tank or vehicle,along with receiver caps, nozzle anchors and operator instruction signs to ensure the safe, trouble-freeoperation of the Banlaw system.

After the nozzle has been connected to the receiver and turned ON, fuel is allowed to pass throughthe fill-point into the tank. Fluid continues to flow at the desired rate until the fuel level reaches thefloat balls at the base of the vent. The balls seal against an O-ring at the base of the 3/4” vent tubeproviding a positive air-tight seal within the tank. Fuel continues to flow until such time as the requiredamount of pressure is developed in the tank - typically 15-100kPa, depending on the spring setting ofthe nozzle, the flowrate and the specific filling application. This pressure is transferred upstreamthrough the nozzle where it is sensed by a patented piston style unit within the nozzle, which promptlyshuts the nozzle OFF thus terminating the flow of fuel into the tank. The nozzle can then be safelydisconnected and mounted in a secure position - such as a nozzle anchor - ready for the next refuellingapplication. A 1/16” bleed hole in the vent valve allows the tank contents to gradually return toatmospheric pressure - typically between 10-60sec - after the vent has closed at the completion ofrefuelling.

To ensure the correct operation of the Banlaw system it is important to provide a constant high flowarea downstream of the nozzle with a minimum of flow directional changes. In addition, the flow of airthrough the vent exhaust should not be impeded by restrictions. Such measures will reduce the linepressure required through the nozzle and maximize the refuelling flow-rate. High ratios of line pressureto flow-rate can lead to premature nozzle shut-down and hence partial tank filling.

All Banlaw products are manufactured in accordance with of standard AS/NZS-ISO9001.