Installation, Operating and Maintenance Instructions for AEON Metal Seated Gate Valve (MSGV) Water

Transcription

1 1 Foreword 1.1 Thank you for choosing one of the range of AEON's BS standard valves. For safety purposes, the user shall read this instruction to fully understand the operation of the product. 2 AEON Design Criteria 2.1 The BS valves are designed in accordance with various BS standards, which ensures that the valve has sufficient strength to accommodate the pressure-temperature rating. The valve has various sealing materials in accordance with BS standards, which are used to avoid corrosion where necessary. The materials and components are designed and assembled to prevent the risk of failure. The Valve is designed to accommodate a hand wheel, gear operator or electric actuator according to its size, torque, and operation requirements. 2.2 What action the user shall take General In any occurrence, first ensure personnel safety Make sure that the selected valve materials are corrosion/wear resistance to the service fluid Where the service fluid is flammable/explosive, to limit the working temperature When performing Repair/maintenance operations, make sure that the valves are always depressurized, vented and drained For actuator operated valves, make sure all supply lines (Electrical, hydraulic, Air) are disconnected before starting any operation When performing Repair/maintenance operations, do not smoke, do not use any portable no-ex-proof electrical device in the area and do not use open fire without a valid work permit Valve must periodically be checked: -Tightness of bolted connection (body/bonnet, gland, flange connection).-corrosion/wear damages (crack, pitting, thickness of the valve). Ensure valves are fully opened and fully closed to confirm operability.

2 3 Scope and Technical Parameters: 3.1 Scope: The series valves are widely used in Water and waste water industries for shut off or connection of pipeline. 3.2 Application Standard: Design standard: BS5163 Flange dimension: EN1092-2, BS4504 Structure length: BS5163 Valve testing: EN12266, EN Valve Structure DN50 DN Body 2 Seat Ring 3 Disc 4 Stem Nut 5 Stem 6 Bonnet Gasket 7 Bonnet 8 Holding Ring 9 Seal Ring 10 O-Ring 11 Gland Bonnet 12 Dust Ring 13 Hand Wheel

3 DN350 DN600 1 Body Disc 3 Bonnet 4 Stem 5 Stem Nut 6 Holding Ring 7 Seal Ring 8 Holding Ring 9 Seat Ring 10 Gland 11 Hand Wheel 1 12 Bonnet Gasket 13 Bonnet Bolts 14 O-Ring 15 Seal Ring DN700 DN Body Bonnet 3 Disc Stem Nut 5 Stem Seat Ring 7 Bolts 8 Nuts 9 Washer 10 Bolts 11 Yoke 3 12 Packing 13 Gland 14 Bolts 15 Coupling 16 Gearbox

4 4 Maintenance: 4.1 Dismantling and Servicing Instructions for Gate Valves: Loosen the body/bonnet joint stud/nuts and remove from body, loosen the eye bolt nuts, rotate the hand wheel in clockwise direction. Wedge will come down to closed position. Further rotate the hand wheel in same direction, bonnet assembly will rise in upward direction. Continue the same till spindle comes out of threaded portion of yoke sleeve. Lift the bonnet assembly to separate it from body. Hold the spindle portion above body with left hand and pull it upward by hammering gently on topside of body surface beyond gasket area. The spindle along with wedge will come out of body. Observe the condition of seat portion and interior portion of body. Clean body interior portion and seat surface thoroughly with suitable cleaning liquid check up for any scratches on seat ring surfaces. Minor scratches should be removed by lapping with emery paste with the help of body seat lapping fixture. 4.2 Gate assembly and maintenance procedure: If the scratches are deep which cannot and cannot be removed by lapping, further machining may be required. Where seat rings are seal insert to the body, the complete body should be loaded on to the machine for further rectification. Similarly minor scratches on wedge surface should be removed by lapping with emery paste. Deep scratches should be rectified by machining and lapping. In case the wedge surface is heavily damaged the entire seat surface which should be fully machined or replaced by a new seat ring 4.3 Remove the old gland packing from bonnet stuffing box: Clean the bonnet surface from inside; lap the degree surface of back seat bush with suitable tools or by using the spindle itself. Clean the threaded portion of the spindle. Polish the non-threaded portion of spindle on a lathe machine or dress if required. 4.4 Change the body bonnet joint gasket and assemble the valve: Put new gland packing of required size and quality into the stuffing box with open end 180 degrees with respect to each other. Tighten nut equally on both sides. Lubricate the spindle-threading portion and operate the valve 2~3 times. 4.5 Stem Repair: Valve stems should be repaired due to the following reasons: Straightness (bent, not straight) Damage to head and threads, Corrosion, Pitting and taper in the portion that slides through the packing.

5 4.6 Straightness: Minimum clearance for the length of the stem when measured from a straight edge laid along side the stem, while rotated 360 degrees. The stem should be press straightened if necessary or should be re-machined on a centre less grinder. 4.7 Threads and head: Thickness and smoothness of threads must ensure smooth operation within the stem nut. The head must adequately engage the disc or plug. 4.8 Packing slide area: The area that passes through packing should be free from pits and have a smooth finish. Polishing or turning of the sliding surface within pre-decided limits can achieve this. Also the taper on the stem should be removed. If the pits wear, taper or previous machining results in a reduction of the stem outside diameter beyond the acceptable limit from the original size; then the stem must be replaced by a new one. 5 Valve Operation and Maintenance: 5.1 After installation and for the pressure test of the pipeline or the system, the wedge must be fully opened or fully closed. It is not recommended to partly open the valve for adjustment of flow rate or emergent pressure relief blow-off. AEON is not responsible for damage, loss or expense arising out of such usage. 5.2 Dust, grease and medium residual may accumulate at the surfaces of body, and the moving parts such as stem, gearbox, the guide of yoke etc. can cause wear and erode the valve, and even generate friction heat that is dangerous in explosive atmosphere. These components be cleaned frequently according to the working conditions. 5.3 After being put into service, the valve shall be checked and maintained periodically especially for the condition of the sealing surfaces and wear and tear, the age of the packing and the corrosion of body. In case of such situation, the valve shall be repaired or replaced. It is suggested that inspection and maintenance of valve shall be performed every three if the medium is water and every month or to local law if the medium is corrosive. After reparation, valve shall be re-assembled and adjusted using recommended torque as follows. After reassembly, the valve shall be pressure tested.

6 6 Routine valve inspection 6.1 The valve shall be checked regularly, including the attrited quantity of seat, wedge and stem s thread, the body and the bonnet s corrosive quantity. The packing and the gasket usually shall be replaced after checking as a basic maintenance. 6.2 Valve removal (1) The valve shall be removed in accordance with the accepted drawings. (2) Carry out the following prior to removal: a) The valve s position and condition shall be accurately recorded prior to removal of the valve from the pipeline to prevent operator error. Records shall be kept and maintained. b) Record all relevant information including cast numbers, serial numbers and all details of the failure mode prior to removal. 7 Potential Failure and Troubleshooting Failure (risk) Cause Troubleshooting Leakage of packing 1. Gland flange nuts loose 2. Rings of packing not enough 3. Packing aged or failure 4. Stem sealing damaged Leakage between sealing 1. Dirties between sealing surfaces surfaces 2. Sealing surfaces damaged Operation failure 1. Packing too tight 2. Thread of stem nut over worn 3. Stem bent 4.Foreigner existence between stem and stem nut or gland or gland flange Leakage between bonnet 1. Bonnet bolts loose 2. Bonnet gasket flanges failure Body and bonnet broken 1. Water hammer 2. Fatigue 3. Freezing and leaked broken 1. Equally tighten eyebolt nuts 2. Add packing 3. Replace packing 4. Stem shall be maintained periodically 1. Clean sealing surface 2. Repair the sealing surfaces 1. Proper loose gland flange nuts 2. Replace stem nut 3. Rectify or replace stem 4. Clean foreign matter 1. Proper tighten bonnet nuts 2. Replace bonnet gasket 1. Carefully operation to prevent suddenly stopping pumping and rapidly shutting. 2. Replace valve that exceeds

7 8 Precautions to be taken Whenever the gland packing is required to be replaced under full working pressure, ensure that back-seating arrangement is present and is functioning properly. While opening and closing of the valve please check direction of turn for open and close(operation in opposite direction may damage the yoke sleeve). When body bonnet joints are unbolted do not forget to use a new gasket when refitting. 9 Valve Transportation 9.1 Check the package of valve before transportation is in accordance with the related standard. Rotating the hand wheel should be avoided when the valve has been packaged. 9.2 Actuator and valve shall be packaged separately. 9.3 The valve is heavy, suitable lifting equipment shall be used during transporting. When lifting the valve, the cord shall be tied to the yoke, do not tie to the hand wheel or the stem. Handle the valve carefully to avoid any damages. 9.4 The paint, name plate and the sealing face of flange shall be protected during the transportation. Do not drag the valve along the ground, especially on the flange sealing face. 9.5 The valve shall be stored safely to prevent rain, dust and grease contamination prior to installation. Ensure the valve is in the fully closed position. If the valve is accidently opened, the sealing face of the seat and wedge shall be cleaned, then the valve should be closed. 10 Valve Storage 10.1 The valve shall be stored in ventilated and dry storehouse for protection. It is not permitted to store the valve outdoors in any situation. Valve end flanges shall be blanked with covers Don t mark the stem when moving the valve. The packing box must not be in contact with the shelf if the valve is stored on the shelf. It is recommended not to store the valve on the ground directly The valve shall be stored with the gate closed. The seal face must be kept clean to avoid scratching when the valve is stored for long time periods. Checking / cleaning of the valve if the valve has been stored for over six months. Repeat pressure tests must be completed prior to installation if the valve has been stored over twelve months.

8 11 Valve Installation 11.1 Carefully check valve identification against valve specifications before installation Check the inside of bore and the sealing surface before installation, any debris shall be removed with a clean soft cloth Check the sensibility of actuator to prevent seizure before installation Valve operation device is recommended to be installed at location 1.2m from the ground for convenience of operation. Where the centre of the valve and the hand-wheel is over 1.8m from the ground, a platform shall be built for the frequently operated valve. For pipeline with numbers of valves, valves shall be installed on the same platform as likely as possible for convenient of operation. For single valve installed at location over 1.8m and less operated, apparatus may be used such as chain-wheel, extension bar, move platform and move ladder etc. Where valve is to be installed underground, extension bar or ground-well shall be set. For safety reasons, the ground-well shall be covered For valve installed on horizontal pipeline, the stem must be in the upright position; or the downward stem shall be difficult for operation and maintenance, as well the valve being liable to corrosion. If the ground valve is slant installed, the operation and maintenance shall also be difficult. If the valve will be installed horizontally, the purchaser shall put forward definitely at the spec book for purchasing, or else AEON will not take responsibility for the expense which cause by installing horizontally When valves are installed in pipeline side by side, enough space shall be considered for operation, maintenance and disassembly. The clearance of hand-wheels shall not less than 100mm; in case of narrow clearance, valves shall be installed interleaving.