Bray/ VAAS Unidirectional Series Knife Gate Valve 940/950 ...... · 6 Remove the old packing (3) from the packing chamber, one layer at a time, using a long thin tool to pry it out

Bray/ VAASUnidirectional Series Knife Gate Valve

940/950/952/980/985 SeriesOperation and Maintenance Manual

Table of Contents

Definition of Terms 1

Safety Instructions 1

Introduction 2

Unpacking 2

Storage 2

Installation 3

Commissioning 3

Cylinder-Operated Valves 3

Manual Valves 3

Maintenance 4

Lubrication 4

Packing Replacement 5

Seat Replacement 6

Actuator Maintenance 7

Spare Parts 7

Packing Details 7

Troubleshooting 8

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Unidirectional Series Operations and Maintenance Manual

1

Unidirectional SeriesOperation and Maintenance Manual

Definition of Terms - Safety Instructions

READ AND FOLLOW THESE INSTRUCTIONSSAVE THESE INSTRUCTIONS

DEFINITION OF TERMS

Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury

Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury

NOTICE Used without the safety alert symbol indicates a potential situation which, if not avoided, may result in an undesirable result or state, including property damage

HAZARD-FREE USEThis device left the factory in proper condition to be safely installed and operated in a hazard-free manner The notes and warnings in this document must be observed by the user if this safe condition is to be maintained and hazard-free opera-tion of the device assured

Take all necessary precautions to prevent damage to the valve due to rough handling, impact, or improper storage Do not use abrasive compounds to clean the valve, or scrape metal surfaces with any objects

The control systems in which the valve is installed must have proper safeguards to prevent injury to personnel, or damage to equipment, should failure of system components occur

QUALIFIED PERSONNEL• A qualified person in terms of this document is one who is familiar with the installation, commissioning, and operation

of the device and who has appropriate qualifications, such as:

• Is trained in the operation and maintenance of electrical equipment and systems in accordance with established safety practices

• Is trained or authorized to energize, de-energize, ground, tag, and lock electrical circuits and equipment in accordance with established safety practices

• Is trained in the proper use and care of personal protective equipment (PPE) in accordance with established safety practices

• Is trained in first aid

• In cases where the device is installed in a potentially explosive (hazardous) location – is trained in the commissioning, operation, and maintenance of equipment in hazardous locations

2

Unidirectional Series Operation and Maintenance Manual

The valve must only be installed, commissioned, operated, and repaired by qualified personnel.

The device generates a large mechanical force during normal operation.

All installation, commissioning, operation, and maintenance must be performed under strict observation of all applicable codes, standards, and safety regulations.

Observe all applicable safety regulations for valves installed in potentially explosive (hazardous) locations.

INTRODUCTIONThe Bray/ VAAS Series 940/950/952/980/985 provides repeatable unidirectional shutoff in a rugged, single-piece cast body

Featuring both metal and soft seating, the Bray/ VAAS Unidirectional Series gate valve caters to all types of unidirectional sealing requirements across a wide range of industries

Additional information about Unidirectional Series valves – including application data, engineering specifications, and actuator selection is available from your Bray/ VAAS distributor or sales representative

UNPACKINGEnsure the box is not damaged externally Remove the valve from the packaging and check for any damage to the valve and its components during transit

Valve size and brief material specification of body (markings such as “SS” or “DI”) are marked on the valve body A stainless steel nameplate (below) afixed to the yoke of the valve contains most of the relevant information on the valve including Bray/VAAS work order number and unique serial number of the valve These details should be quoted for all requirements of service and spares

SERIAL NUMBER

SIZE MODEL FLG. DRILL BODY GATE

SEAT PACKING CWP MAX TEMP

STORAGEWrap the valve with a polyethylene cover Cover the ports for pneumatic actuator/accessories with plastic caps Store these valves in the same packing indoors and without direct exposure to the environment

If the valve is to be stored for a long period of time before installation, it should be stored in a vertical position (preferable) and in a cool, clean area to prevent damaging effects on the packing

Gate should be off the seat to prevent compression set

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INSTALLATION

• Valves can be mounted with flow in one direction Flow directions are indicated on the valve as these would depend on the application for which the valve is used However, to enable correct orientation, the seat side of the valve can be identified with the word “SEAT” marked on the body and on the gate top side

• On horizontal lines, if there is a possibility of particles/solids settling at the bottom, it is preferable to install the valve so that the stem is above horizontal/inclined/vertical

• Install the valve between flanges using fasteners & gaskets

• Bolt holes in the chest area are always blind tapped and care should be taken not to bottom the bolts while tightening Refer to GA Drawing/ Technical Bulletin for quantity and size of blind tapped holes on valve chest area If the correct size bolts are not available, use studs and nuts for chest area bolts to avoid damage of body

Support should be used for valves size 8” and over when installed in vertical pipe Failure to do so can result in improper valve operation and/or valve failure

COMMISSIONING GUIDELINES

• Gland packing is tightened to hold the specified pressure and tested for no leakage before dispatch However, this may require some adjustment at site due to loosening in transit etc

• Check for gland leakage after the valve is subjected to pressure and if any leak is observed, tighten the gland uniformly in a cris-cross pattern until the leakage stops

Wrong electrical supply to accessories will damage the equipment Do not over tighten the gland nuts as this may cause excessive friction and premature damage to packing

Cylinder Operated Valves1 Connect instrument quality air, preferably through an air filter/regulator of adequate size The recommended air pres-

sure is 80-120 psi (5-8 bar) Refer to the appropriate bulletin/drawing for port and cylinder size details 2 Ensure the supply air is free from moisture, dirt, and other foreign particles Drain the filter regulator before operating

the actuator so that pipe rust and dirt if any in the air line will be removed before actuation 3 If valves are supplied with electrical accessories like limit switch and solenoid valve, ensure wiring is done as per local

electrical safety codes and regulations Ensure correct electrical supply is given to electrical accessories for proper func-tioning and safety of the equipment

4 Open the valve by energizing the solenoid valve/giving air supply to cylinder and operate the valve 2-3 times

Manual valvesOpen/Close the valve manually and observe valve operation

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MAINTENANCE

NOTICE

Any modification or use of unauthorized parts voids any and all warranty considerations

LubricationThe manual valve stem should be lubricated at regular intervals for smooth operation of the valve A lubrication nipple is provided on the collar Cylinder operated valves do not require routine lubrication

NOTICE

If the cylinder actuator is disassembled for repair, the cylinder wall and seals need to be lubricated with a lithium-based grease prior to reassembly

Manual Valve Stem Cylinder Actuator

5


Packing Replacement

Relieve line pressure before loosening gland nuts to avoid injury and/or equipment damage

1 Relieve the line pressure

2 Fully close the valve

3 Ensure the line is empty, and flush if necessary

Manual Valves1 Ensure the valve is fully closed

2 Disconnect the stem from the gate (2) by removing the clevis bolts & nuts (6)

3 Rotate the Handwheel (1) counter-clockwise by holding the stem from rotation, so that the stem retracts fully from the gate

4 If valves are supplied with bellows, ensure stem is not rotating, as rotation will damage the bellows

5 Remove the gland nuts (5) and the gland (4)

6 Remove the old packing (3) from the packing chamber, one layer at a time, using a long thin tool to pry it out

7 If the lowest layer is a wiper ring (copper, Inconel etc ), clean it with a common solvent; if damaged, replace with a new one

8 Insert the new packing one at a time ensuring that the gate (2) is in full contact with the seat (gate fully down) and not rubbing the bottom of the packing chamber Stagger the cut end of the packing so they do not line up

9 Tap each packing (3) ring firmly and evenly into the chamber before installing the next ring; the ends of each ring should meet but not overlap

10 Install the packing gland (4) and gland nuts (5)

11 Ensure the gap between the gland and the gate is uni-form all around

12 Tighten the gland nuts (5) finger tight plus one half turn

13 Lower the stem by rotating the handwheel clockwise while holding the stem and fasten the stem to the gate with nuts and bolts

Cylinder operated valves1 Switch off the electrical supply to the solenoid and limit switches

2 Remove the cylinder tubing and vent the air inside the cylinder

1

5

4

3

2

6

6


3 Disconnect the piston rod from the gate by removing the clevis bolts & nuts

4 Apply air slightly to the bottom port of the actuator so that the piston rod is retracted from the gate

5 Remove the actuator assembly from the valve by removing the fasteners connecting the yokes to the valve body

6 Remove the gland nuts (5) and the gland (4)

7 Remove the old packing (3) from the packing chamber, one layer at a time, using a long thin tool to pry it out

8 If the lowest layer is a wiper ring (copper, Inconel etc ), clean it with a common solvent; if damaged, replace with a new one

9 Insert the new packing one at a time ensuring that the gate (2) is in full contact with the seat (gate fully down) and not rubbing the bottom of the packing chamber Stagger the cut end of the packing so they do not line up

10 Tap each packing (3) ring firmly and evenly into the chamber before installing the next ring; the ends of each ring should meet but not overlap

11 Install the packing gland (4) and gland nuts (5)

12 Ensure the gap between the gland and the gate is uniform all around

13 Tighten the gland nuts (5) finger tight plus one half turn

14 Mount the actuator assembly to the valve by attaching the fasteners connecting the yokes to the valve body

NOTICEIf leakage is observed from the packing area after installing the valve in the pipeline and the valve is pressurized or charged with media, tighten the gland nuts evenly side to side just enough to stop leakage Do not over-tighten the gland nuts

Seat Replacement

Relieve line pressure before attempting to remove the valve from the line to avoid personnel injury and/or equipment damage If the valve has a pneumatic actuator, solenoid valve, limit switches, or other accessories, disconnect electrical and pneumatic supply

1 Relieve the line pressure and close the valve Flush the line if necessary

2 Remove the valve from the line by loosening the flange mounting bolts, studs, and nuts

3 Clamp the valve in the vertical position to a fixture Do not block the valve port when clamping the valve An overhead hoist may be needed for larger size valves

4 Disconnect the stem from the gate by removing the clevis, bolts, and nuts

5 Remove one set of superstructure bolting and tilt the super structure to one side as shown at right

6 Lift the gate up until it fully clears the seat area and remove the old seat by tilt-ing the top of the seat away from the body

7 Insert the new seat with the bottom part first and lower the gate fully

8 Bolt the super structure to the body again and then fasten the stem to gate bolts

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Packing Details

Valve size, inch Packing Size, mm Length, mm Quantity2 Sq 8 180 33 Sq 10 225 34 Sq 10 280 35 Sq 10 330 36 Sq 10 395 38 Sq 10 490 310 Sq 10 580 312 Sq 10 690 314 Sq 12 7 765 316 Sq 12 7 975 318 Sq 16 1005 320 Sq 16 1120 424 Sq 16 1320 428 Sq 19 1520 430 Sq 19 1640 432 Sq 19 1830 434 Sq 19 1950 536 Sq 19 2035 5

ACTUATOR MAINTENANCE

Pneumatic CylinderThe Bray/VAAS pneumatic cylinder actuator is a low maintenance design and does not require routine maintenance It has an FRP tube which is lubricated for life with a special coating on the inside wall Filtered dry, instrument quality air (non-lubricated) should be used for its operation at the specified air supply pressure

Recommended spare partsFollowing are parts recommended as spares, which may be stocked Following are general recommended spares for valves Provide the valve serial number and work order number from the nameplate for proper parts

• Gland packing

• Spare Seat

• Cylinder repair kit

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Troubleshooting

Trouble Possible cause Solution

Media oozing out of gland packing Packing deteriorated Replace packing

In fully closed position, valve leaks

Seat is worn out or torn Replace seat

Gate is scratched Replace gate

High torque during valve seating and unseating

Misalignment between gate and stem

a) Remove the clevis fastenersb) Loosen the superstructure fastenersc) Adjust the alignment of the stem and gated) Connect the clevis fastenerse) Retighten superstructure fasteners

Packing is not tighten properly Adjust gland nuts

Valve jerks during open and close

Superstructure fasteners loosen Tighten the super structure fasteners

Insufficient air supplyPneumatic operated valves: Increase supply pressure

Solenoid valve dust accumulation Remove and clean solenoid valve

Piston rod seal damaged Replace seal

Unable to close or open the gate Gate is bent

a) Check for valve orientation, flow direc-tion and flow indicationb) Re-orient the valvec) Replace gate

All statements, technical information, and recommendations in this bulletin are for general use only Consult Bray/VAAS representatives or factory for the specific requirements and material selection for your intended application The right to change or modify product design or product without prior notice is reserved Patents issued and applied for worldwide

Bray® is a registered trademark ofBray International, Inc © 2015 Bray International, Inc All rights reserved

OM_Series_940_12_20_2016

Bray/VAASDivision of Bray International, Inc 13333 Westland East Blvd Houston, Texas 77041Tel: 281 894 5454 • www bray com

Documents

Bray/ VAAS Unidirectional Series Knife Gate Valve 940/950 ...... · 6 Remove the old packing (3) from the packing chamber, one layer at a time, using a long thin tool to pry it out