Operating instruction

Transcription

1 Operating instruction MV, XV, HG, HP, RKO, D2G, TV, BV, WB & SLV 1 Introduction 2 2 Stafsjö s knife gate valves 2 3 Technical information Pressure test Labelling 2 4 Storage 3 5 Transportation and handling Lifting and moving 3 6 Installation Installation in an ATEX-classified area Surrounding environment Pressure and valve direction Support Actuators Lifting and moving during installation Installation between flanges Re-tightening of the gland 7 7 Operation 7 8 Service and maintenance Maintenance Troubleshooting 8 9 Spare parts and accessories 9 Information is only for informational purpose. All specifications are subject to change without notice. 1 Stafsjö Valves AB. SE Stavsjö, Sweden. Tel: Fax: info@stafsjo.se A Bröer Group Company

2 1 Introduction The operating instruction describes how Stafsjö s knife gate valves shall be installed and operated to ensure the products function and safety during its lifetime. The operating instruction shall be made available to persons responsible for handling, installation, operation, service and maintenance of Stafsjö s knife gate valves. More detailed information on specific knife gate valve, its actuator and accessories is available in data sheets and service instructions at. You can also contact Stafsjö or your local representative. Stafsjö accept no responsibility for the product if this operating instruction is not followed during handling, installation, operation and maintenance. Neither accept Stafsjö no responsibility for the knife gate valve if has been modified from its original condition. 2 Stafsjö s knife gate valves Stafsjö s product range consist of several models in sizes DN 50-DN Our valves are known by their quality, tight and reliable shut-off and flexible design. Fully modular design making it easy to uphold excellent operation year after year and making it also easy to equipe the valves with different actuators and accessories. The knife gate valve is designed of a one piece or a two piece valve body. The gate is made of stainless steel and the seat/sealing profile sealing towards the gate is available in different materials. Stafsjö s proven box packing, TwinPack, which is held into to place by the gland gives a tight sealing and assures high operation reliability. 3 Technical information The knife gate valves, actuators and accessories are described in different data sheets. Limitations of the products are given in data sheets which are available at. If you have any questions regarding use of knife gate valve in a specific application, please contact Stafsjö or your local representative. 3.1 Pressure test According to each Data sheet, all knife gate valves of Stafsjö have been pressure tested. 3.2 Labelling Each knife gate valve of Stafsjö is labelled with: - An article number. - A serial number that consist of year-individual number-order number. The label should not be removed. Serial number has to be stated in contact with Stafsjö regarding a specific knife gate valve. 2

3 4 Storage The knife gate valve shall be stored in a clean and dry environment. It should be protected against dirt, dust and other pollutants. Neither should it be exposed to direct sunlight. Keep the valve in open position during storage to ensure its function. If the knife gate valve is stored outside, it must be wrapped up in plastic or similar to be protected against moisture. It should also be stored high enough, without any risk to be covered in snow or enclosed by water. Never place lifting equipment: On the actuator, accessories or gate guards. In the bore of the knife gate valve, since it cause damages to the seat and retainer ring. 5 Transportation and handling The knife gate valve has been packed according to the conditions of the transport for the delivery. Unfortunately damage can occur to the product due to mishandling during the transportation. It is important to make a visual inspection of the valve at arrival. If transport damages are detected a report has to be written to the transportation company. 5.1 Lifting and moving When lifting and moving the knife gate valve, you always have to use two or more metallic lifting eye bolts. These lifting eye bolts must be screwed into the holes of the flange drilling. The lifting equipment has to be attached to the lifting eye bolts. Before lifting you must always check: That the lifting equipment is safe and is designed to hold the weight of the valve. That the lifting eye bolts corresponds to the flange drilling and they securely tightened. That the actuator, accessories or gate guards are not exposed to blows or thrusts. That the weight of the valve is not exerted to the actuator, accessories or gate guards. No work is allowed in the pipe line or on the knife gate valve when the system is pressurized and contains media. The pipe line must be free from pressure and empty before any work begins. The consequence of neglecting the demand mentioned above could involve personal injuries and/or damage to the pipe line or the knife gate valve. 6 Installation Before installation of the knife gate valve in the pipe line, the following must be checked by the owner of the plant: That the pipe line in which the valve is to be installed in is empty and free from pressure. That the operation data of the application (temperature, pressure etc) do not exceed the maximum allowable values for the valve. That the valve materials correspond to the operating conditions of the media/application That surrounding environment does not imply any risks to the valve, actuator or accessories. That flanges, pipe and the valve are free from deposits and other solid particles. 3

4 6.1 Installation in an ATEX-classified area Only knife gate valves with ATEX-classifacation may be installed in an ATEXclassified zone in accordance with ATEX dir 94/9/EG. The following have to be checked if an ATEX-classified knife gate valve of Stafsjö is going to be installed: The knife gate valve is ATEX-labelled and the ATEX-classification corresponds to the plants classification. The operation data of the application (temperature, pressure etc) does not exceed allowable values of the knife gate valve. The knife gate valve is part of the plants earthed system. The user has performed a risk analysis of the pipe line and knife gate valve in accordance with the guidelines of ATEX dir 94/9/EG. These instructions is valid along other instructions in this document. 6.2 Surrounding environment The environment around the knife gate valve should be dust free and dry. Too high or low temperatures or quick temperature swings may affect function of the valve together with actuator and accessories. The knife gate valve must be protected against radiant heat if the valve is placed near a heat source whose temperature exceed maximum allowable temperature for the valve or its actuator. The knife gate valve must be protected against leakage of gas and fluid from surrounding environment. Gas or fluid can affect materials in the valve and function of actuator and accessories. P1 SEAT SIDE P2 6.3 Pressure and valve direction When the knife gate valve is open; P1=P2 may not exceed maximum allowable working pressure body according to each valve. When the valve is closed, the differential pressure P, is the difference between P1 and P2 ( P = ± (P1-P2)). The differential pressure P may not exceed maximum allowable differential pressure according to each valve. The knife gate valve MV has different differential pressure P capacities in the two directions. The maximum P of the valve is achieved when the seat side is installed towards P2, provided that the flow direction is from P1 to P2. When the valve is closed, the pressure ratio shall be P1>P2. Some sizes of the MV valve also handle a certain reversed pressure. See the data sheet for maximum allowable differential pressure from the seat. The knife gate valve TV shall be installed with the seat side to the tank. The removable retainer ring shall be mounted against the tank which means that changing seat in the valve can only be done when the tank is empty. When the TV valve is closed, it has a limited differential pressure P2>P1. See the data sheet for maximum allowable differential pressure from the seat. 4

5 The knife gate valve RKO shall be installed in a vertical pipe line with a circular inlet and a square outlet. See maximum allowable differential pressure in the data sheet. The knife gate valve D2G shall be installed in a vertical pipe line. It is independent of the differential pressure direction when the valve is closed. See maximum allowable differential pressure in the data sheet. The knife gate valves XV, HG, HP, BV, WB and SLV are bi-directional and can therefore be installed independent of the pressure ratio in any direction in the pipe line. For closed valve, see maximum allowable differential pressure in the data sheets. 6.4 Support The knife gate valves MV, XV, HG, HP, BV, WB, SLV and TV should be installed in a horizontal pipe line with the actuator in a vertical upright position. If the knife gate valve is installed in any other direction, the dead weight of a long gate or a large actuator may cause tensions in the valve that could affect tightness and the valves ability to actuate. Valves that are exposed to vibrations or other mechanical stresses can be subject to forces that will affect valves tightness and ability to manoeuvre. In these cases, the knife gate valves and actuators should be supported to avoid function failure. Supporting can preferably be done by mounting a loop and suspension in a wire or supporting by using a fastened rod. The wire or rod should be placed on the yoke for the actuator. 6.5 Actuators Manual actuators are not mounted on the knife gate valve at delivery. The hand wheel shall be mounted on the valve with a locking nut. Before mounting the hand wheel on the knife gate valve, control that there is not any play between the actuator, bearing and actuator yoke. The play appears between the stem and stem nut when the stem changes direction of rotation. Eliminate the play before mounting the actuator by rotating the stem 360 degrees counter clockwise. See figure. Automatic actuators shall be installed, operated and serviced by qualified personnel according to the instructions of the manufacturer which comes with the actuator. The instructions must be followed carefully for safe operation of the knife gate valve. The gate guards must always be installed on the knife gate valve with an automatic actuator Stafsjö accepts no responsibility for the product if actuators not tested and approved by Stafsjö are mounted on the knife gate valve. 6.6 Lifting and moving during installation When installing the knife gate valve into a pipe line, all lifting and handling shall be carried out with soft straps. The soft straps shall be placed and 5

6 fastened under the valve body beam surface. The beam surface is the place on the valve body where the gland and/or the beams are attached. It is also possible to place a soft strap around the yoke for the actuator but never place a strap on the actuator. Before lifting you must always check: That the lifting equipment is safe and designed to hold the weight of the valve. That the soft straps are fastened and do not risk to slide along the valve. That the actuator, mounted accessories or gate guards are not exposed to blows or thrusts. That the weight of the valve is not exerted to the actuator, mounted accessories or gate guards. The XV valve must be closed at all time during installation. The SLV valve must be open at all time during installation. SLVs bottom lid is only allowed to be mounted on the valve when flushing is made through the purge ports in the valve body. 6.7 Installation between flanges The knife gate valve is delivered ready for installation between flanges. The XV valve must be closed at all time during installation, while the SLV must be open at all time. Also note that SLVs bottom lid is only allowed to be mounted on the valve when flushing is made through the purge ports in the valve body. The knife gate valve shall always be installed between two full flanges (fixed or loose) to ensure that the valve is secure and that the flange keeps tight. The contact surface of the flange must cover the retainer ring of the valve completely, to get a uniform surface pressure between the valve and the flange. Detailed information on the valves flange drilling with dimensions, thread, length and number of bolts is available in data sheet at. If a knife gate valve is installed as an end valve in a pipe line, always use a counter flange to secure the valve and keep the flange free from leakage. If you install a knife gate valve as an end valve in a pipe line, always install protective equipment to prevent people getting to close to the valve and being exposed to the media transported in the system when the valve opens. When the knife gate valve is installed in the pipe line, the valve centre line must be on the same centre line as the flanged pipes. The valve must also be placed parallel between the flanges. If the flanges and the valve are not centred, the valve may be damaged by erosion and a dirt pocket may occur which can lead to clogging and corrosion of the valve. When the pipe system is pressurized and the temperature increases, leakage can occur in the flange. If there is any leakage, the flange bolts have to be re-tightened to make sure the flange keeps tight. 1. Place the gasket between the valve body and the flange, check that the packing is well centered and covers the complete surface of the retainer ring. WB and SLV are equipped with flange gaskets and additional are not necessary. 2. Choose bolts with the correct thread and length. Too tall bolts could deform the valve body and result in leakage in the flange. Too short bolts could deform the threads. 3. Lubricate the bolts. The grease gives better pre-stressing of the flange and makes it easier to dismantle when needed. 4. Tighten the bolts manually and then evenly and crosswise to obtain an evenly divided load on the flange. 6

7 When the pipe system is pressurized and the temperature increases, leakage can occur from the gland box. If this occur, re-tighten the gland nuts and make sure the box packing keeps tight. The gland nuts may only be loosened when the system is free from pressure T G DN Nm lbf x ft Make sure that the valve, gasket and flanges are parallel and on the same centre line. Adjust if needed. 6. Finish the valve installation by tightening the bolts evenly and crosswise to full moment. 7. Make an operational test by opening /closing the valve. 6.8 Re-tightening of the gland The box packing seals the valve from the surrounding environment at the gate. During transportation between manufacturing and customer, the box packing settles which could result in leakage after installation if the gland is not re-tightened. If the box packing is leaking, re-tighten the nuts on top of the gland bit by bit and crosswise until the leakage stops. Tighten the nuts evenly; it is important that there is no contact between the gland and the gate. Do not tighten the nuts too hard since it will affect the valve s ability to operate and shortens the life time of the box packing. The torque TG in the table is a recommended value for tightening the gland nuts. More information on changing of box packing and tightening of box packing is available in service instructions at. 7 Operation Before the knife gate valve is put into operation, you must control: Gate guards must always be installed on the knife gate valve with an automatic actuator in order to prevent personal injuries before the valve is put into operation. That the operating data of the system doesn t exceed maximum allowable value of the knife gate valve. Those materials in the valve are chosen with regards to the media in the system. That the knife gate valve is installed in correct direction in relation to the direction of pressure when the valve is closed. That the knife gate valve is centered and parallel to the pipe line flange. That the knife gate valve is equipped with sufficient support to avoid tensions. That the actuator is installed according to the instructions of the manufacturer and carried out by qualified personnel. That the accessories are installed correctly by qualified personnel. The surrounding environment and the system in which the valve is installed shall have normal operating conditions to obtain the optimal function and lifetime of the knife gate valve. When operating the valve, you must on a regularly basis control: That the environment around the knife gate valve does not imply any risks to the valve, its actuator or accessories. That powerful pressure, temperature and vibration swing is avoided in the system. That the staff is observant to leakage from the pneumatic cylinder and if it occur action is taken immediately. 7

8 That the pneumatic cylinder or its accessories are exposed to external loads or other strains. 8 Service and maintenance No work is allowed on the knife gate valve when the pipe line is pressurized or the automatic actuator is connected. The system must be empty and free from pressure before work begins. The actuator and accessories must be disconnected before work begins. The gate guards must always be installed on the knife gate valve before the valve is put into operation after completed work. People s life and health is at stake if this is not followed. 8.1 Maintenance Seat and box packing are wear parts that have to be replaced regularly to keep the knife gate valve tight and free from leakage. The interval for replacement depends on the application and operating data such as pressure, temperature, erosion and chemical and mechanical effect of the media on the materials in the knife gate valve. The knife gate valve must be inspected every day for leakage and other external effects that could affect personal safety, the valve, its actuator or accessories. A full scale manoeuvre test shall be performed at least two times a year to verify that the knife gate valve functions correctly. If a fault or problem is detected at an inspection or manoeuvre test, the knife gate valve should go through service and maintenance as soon as possible. Information on spare parts and instructions for service and maintenance are available at. 8.2 Troubleshooting Faults or problems that are detected on the knife gate valve may have several reasons. The most common problems and their reasons are listed in the table below. To remove the problem, the knife gate valve should undergo service and maintenance. How to perform the service, maintenance and available spare parts is described in Service instructions and Spare part data sheets at. If you cannot find the information you are looking for, please contact Stafsjö or your local representative. Problem Reason Measure Leakage in box packing Loose box packing Worn-out box packing Incorrectly installed box packing Damaged/bad gate Leakage in flange Wrong length of bolts in flange Loose flange Valve not centred in flange See Operating instruction See Data sheet and Service instructions Valve not parallel in flange Gasket not centred Wrong material in gasket Leakage through knife gate valve Worn-out seat Gate do not close Damaged seat/gate Gate does not Fault in actuator See instruction for actuator/ 8

9 open/close completely Gate does not open/close in a soft movement Abnormal large force to open/close gate Fault in limit switches Valve clogged Damaged seat/gate Fault in actuator Valve clogged Damaged seat/gate Not enough instrumentation air flow/feeding pressure Valve exposed to stress/tension Valve clogged Damaged seat/gate accessories See instruction for actuator See Operating instruction Stafsjö accept no responsibility for the product if wear parts not tested and approved by Stafsjö are installed on the knife gate valve. Neither accept Stafsjö any responsibility for the product if service instructions are not followed when during service and maintenance. Stafsjö offers service and maintenance of knife gate valves, either in the customer s plant or at the Stafsjö workshop. Please contact Stafsjö or your local representative for more information. 9 Spare parts and accessories Spare parts and instructions for service and maintenance are available at. Only Stafsjö s approved original spare parts are allowed to be used. Accessories shall be installed, operated and serviced by qualified personnel. Instructions for accessories can be received from Stafsjö by stating article and serial number with which the knife gate valve is marked with. Stafsjö accepts no responsibility for the product if accessories are mounted on the knife gate valve in such a way that it essentially affects the knife gate valve design or function. 9