XTV Trip Valves

7/29/2019 XTV Trip Valves

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Weir Valves & Controls UK LtdBritannia Works, Birkby, Huddersfield. HD2 2URTel: +44 (0) 1484 820820 Fax: +44 (0) 1484 820484

IOM-B17-R1

Refer to Safety With Valves

Before Starting Work

INTRODUCTION

The XTV range of valves are typically designedfor use with actuators where air flow to and fromthe actuator must be re-routed to either vent, lockor apply the air. The XTV 5 unit is mostly used on

single acting actuators. The XTV6 and XTV7units, being true 6 port valves, are used on doubleacting cyliners where both sides of the cylindercan be independently controlled. The XTV7 valvehas an additional manual override.

The valves have been designed to be fullyadjustable,compact and rugged, and give a quickresponse to changes in pilot pressure.

SPECIFICATION

Port Sizes NPT (Female).

Pilot Port Size 1/8 NPT (Female).

Maximum Pressure - 8.3 Bar (120 PSI).

Temperature Range - -200C to +800C(aluminium body).

Temperature Range - -400C to +80

0C

(316 St.St. body).

Trip Pressure Adjustable Between 0 and7.6 Bar (110 PSI).

INSTALLATION

These valves can be mounted in any orientation.Clean all pipe lines to remove any dirt or foreignmatter before installation. Apply sealingcompound to the male threads of the fittings to beconnected to the valves, making sure nocompound can enter the orifice of the fittings.Installation should be so as moisture cannot enterthe vent holes but do not block these holes. Theuse of PTFE tape should be avoided as particlesof tape can become trapped in the valve andinhibit its function.

ADJUSTMENT

The trip valves are factory tested but not set toany specific trip pressure unless called for. Onceinstalled adjustment to the trip pressure can bemade by means of the adjusting screw (8). Byturning the screw clockwise the trip pressure will

increase and by turning it counter-clockwise thetrip pressure will decrease. After final adjustmentis made ensure the locknut (9) is tightened toavoid accidental movement of the adjustingscrew.

MATERIALS

Block - AluminiumSpring Housing - AluminiumDiaphragm Housing - AluminiumCartridge Assembly - Aluminium/Brass/Buna NSprings - Plated SteelDiaphragms - Reinforced Rubber

Fastening - Stainless SteelAlternative materials such as Stainless Steel orNon-Copper specifications are available enablingextension of operating temperature range downto -40C at intermittent operation, not continuous.

ContentsPage

Introduction 1

Specification 1Installation 1Adjustment 1Materials 1Operation 2

XTV5 Spring Return Actuators 2XTV6 Double Acting Actuators 2XTV7 Manual Override 2

Maintenance 3

Disassembly 3Assembly 3XTV7 Maintenance 3Setting the Trip Pressure 3


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MAINTENANCE

Disassembly

1. Disconnect all air supplies and removethe valve from the pipework.

2. Slacken off the adjusting screw (8) until alltension has been removed from theinternal spring.

3. Remove screws (10) and lift the springhousing (4) off the valve. Take care whenhandling small parts as these can easilybe lost.

4. Lift off the disc (5) and diaphragm (16).5. Remove screws (11) and lift off the

diaphragm cover (3).6. The diaphragm (17) and plunger should

now lift free.

7. The cartridge assembly can only bereplaced as a unit. If it is necessary toreplace a cartridge slacken off the twocountersunk head screws (12) and lift thediaphragm base (2) off the block (1).

8. To lift the cartridges (7), blow lowpressure air into the lower section of theblock (1). This should lift the cartridges (7)which can be lifted out of the block (1)along with spring (15).

Assembly

1. Clean all parts and ensure that all traces

of pipe sealing compound have beenremoved from the port connections.

2. Use a dab of silicon grease on spring (15)and locate it in position at the bottom ofthe block (1).

3. Lightly coat the cartridge seats and sealswith silicon grease. Locate the cartridgeassembly (7) into the block (1). Ensurethat spring (15) is correctly located.

4. Screw the diaphragm base (2) to theblock (1) using the countersunk headscrews (12).

5. Locate the plunger (6) so that theplungers will energise the cartridge

assemblies (7). Apply pressure to theplunger to check for free movement of allparts.

6. Centralise the diaphragm (17) anddiaphragm cover (3) on the diaphragmbase (2). Lock the diaphragm cover inplace with cap screws (11).

7. Place the spigot side of the disc (5)against the diaphragm (16) and centralise

the two items on the upper side of thediaphragm cover (3).

8. Drop the spring retainer (13) and spring(14) into the spring housing (4) and lock

these parts to the diaphragm cover (3).

XTV 7 Maintenance

The XTV 7 unit is fitted with an air equalisingvalve. To maintain the diaphragm (18), unscrewcapscrews (20) and remove the equalising base(19). The diaphragm (18) can be removed andreplaced.

To assemble locate the diaphragm (18) andequalising base (19) over the screw holes andlock in position using capscrews (20).

Setting the Trip Pressure

Apply a regulated air supply to the inlet port(s)and pilot port. Adjust the pilot air pressure until thevalve trips. Turn the adjusting screw (8) asnecessary to reduce or increase the trip pressure.Repeat these actions until the correct trippressure has been set.

Item Description Item Description1 Block 12 Screws2 Diaphragm Base 13 Spring Retainer3 Diaphragm Cover 14* Spring4 Spring Housing 15* Spring

5 Disc 16* Diaphragm6 Plunger 17* Diaphragm7* Cartridge Assy. 18* Diaphragm8 Adjusting screw 19 Equalising Base9 Locknut 20 Capscrews10 Capscrews 21 Equalising Disc11 Capscrews 22 Equalising Screw

* Recommended Spares for Valve


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XTV 5

XTV 6

XTV 7

XTV Trip Valves

Documents

Transcript of XTV Trip Valves