RAIMONDI. 3-way globe valve for feedwater heater outlet bypass Installation and Maintenance Instructions

Transcription

1 RAIMONDI Index Introduction 1 1. Verification upon receipt and storage before installation 1 2. Handling 1 3. Installation 2 4. Scheduled maintenance 2 5. Possible damage and relevant solutions 3 6. Disassembly instructions 4 7. Assembly instructions 4 8. Spare parts list 5 9. Enclosures 6 Introduction This manual provides guidelines to be observed for the following operations: storage installation into the pipeline maintenance preservation The manual is intended for the following personnel/staff: plant warehouse staff installers maintenance engineers This symbol means and indicates all matters relating to safety. Please read the warning notices carefully and follow the instructions. These serve to guarantee your safety and to prevent damage to people and property. In addition to the instructions in this manual, specific plant safety regulations must always be followed. It is recommended that this manual is read carefully and entirely, before starting any maintenance, in order to optimize intervention timing, and to ensure that suggested spare parts and gaskets are available in the event of valve assembly. For installation and maintenance operations no specific equipment or tools are required, other than those usually available in the plant. Fig. 1 - Valve lifting and handling Emerson is always at the Customer s disposal for any further technical information. 1. Verification upon receipt and storage before installation When the materials arrive, it is recommended to: Check the integrity of the case. Open the case and verify that there is no damage due to transportation. Do not open the barrier bag (if present). Verify that the contents are those stated on the packing list. Store the valves (unless damaged) in their original packaging. Please observe the following: 1. Store the valves in a closed, clean and dry storage room. 2. Do not place packages directly on the ground. 3. Check the packages every two months. 4. Substitute the silica gel every six months. This is not applicable in the case of barrier bag packages. 2. Handling During handling operations, valves must be lifted and handled as indicated in fig. 1 by using lifting equipment (fasteners, hooks, etc.) that must be sized and selected on the basis of valve weight (indicated in the drawings). If there are any eyebolts in the valve body, these can be used to lift the valve. Do not use any lifting points located on the actuator to lift the valve. These lifting points are to lift the actuator only. Lifting and handling must be done only by qualified personnel. Do not use any lifting straps that are either damaged or of inadequate/unknown size. Emerson reserves the right to change the contents without notice RAIIC-0052-EN-1310

2 3. Installation For correct operation, the valves must be installed in horizontal pipes with the stem in vertical position. If installed in vertical lines or in horizontal lines with the stem not vertical, maintenance is much more difficult. Any installation position other than those indicated may cause incorrect operation and/or rapid deterioration. The following operations must be performed only immediately before the installation: 1. Remove the protection caps of the end faces. 2. Check the upstream and downstream pipeline sections. Make sure that there are no solid particles or any other kind of dirt or debris inside. If necessary, clean carefully by using an air line. 3. Pay attention to the flow direction. Before starting the installation of the valve, please verify that: the valve class is suitable for the required operating pressure, and the materials of construction are suitable for the intended service (type of process fluid). Fig. 2 - Possible installation positions Verify that the flow direction of the line corresponds to the flow direction indicated by the arrow on the valve body. General notes In order to avoid damage during welding and post welding heat treatment, we suggest to disassemble the internal part following the instructions given in section 6 of this manual. In case that one end of the valve is not connected to the line for a period of time longer than half a day, the open end must be properly closed and sealed in order to prevent entry of dirt or debris. Check that there is sufficient space to easily disassemble the valve. Position the valve and verify its alignment with the pipe. Proceed with welding in accordance with the procedure indicated by the engineering company that designed the plant. During site welding of the valve to the pipe, the valve and adjacent piping must be supported so that the pipeline stresses are not transmitted to the valve body. Usually, the first weld layer will be made with TIG, while following weld layers will be made with the appropriate electrode for the valve body material. Welding and stress relieving procedures should conform to the applicable code or standard. Position the valve and verify its alignment with the pipe. Proceed with the welding operation in Protect eyes with appropriate welding masks or goggles during all welding operations. 4. Scheduled maintenance 4.1 Routine inspection Normal check Verify once a month that there is no leakage from packing or in the body/bonnet area. a. In case of leakage from the packing, tighten the appropriate gland nuts and bolts according to the procedures described in the assembly section. b. In case of leakage from the body/bonnet gasket, tighten the bonnet support bolts as stated in the re-assembly procedure. Otherwise de-pressurize the line as soon as possible in order to prevent erosion. Verify bearings greasing and stem thread every two or three months, depending on operating frequency. For actuated valves, refer also to the actuator manual in addition to the above. Preventive Verify the tightness of gland bolts every three months. Grease the stem and bearings every six months for motorized valves and every eight months for hand-operated valves. Check the travel of the gland follower every twelve months. Install a new packing when the end of the travel is approaching. Disassemble critical and/or actuated valves every four years. Verify the sealing surfaces and lap them if necessary. Substitute the bonnet gasket and the packing. Grease the stem. For the actuator, proceed as indicated in its maintenance manual. Emerson reserves the right to change the contents without notice page 2

3 5. Troubleshooting guide Below is a list with the most common problems. 5.1 Leakage from the packing When there is humidity or droplets near the packing area, the stem or the gland, and these cannot be corrected by tightening the gland bolts, you may want continuing the work of the line until the first stop of the plant. In this case, the stem can be set in backseat position, verifying the following: Packing may have hardened. In this case, it must be replaced. The gland is at the end of its travel. This means that the packing cannot be compressed. Packing must be replaced. Scratches, scorings or other marks may be found in the stem. It may also have got bound. In these cases, the stem must be replaced. The gland may be jammed on the stem because of a non-uniform tightness of the gland bolts. Release the gland bolts. Move the gland and set it again; then tighten the bolts progressively. 5.2 Leakage from body/bonnet joint Leakage under operation from the pressure seal joint requires immediate action, since it may cause major damage to the valve rapidly. Typical causes for leakage are: Previous incorrect reassembly of the valve. Re-using pressure seal gasket. A defect inside the valve body. 5.3 Leakage between seat and disc In case of leakage between seat and disc, we recommend to perform closing and opening operations with a pressure differential. If leakage persists, check that: No foreign material is locked between seat and disc, scoring the sealing surfaces. No foreign material is deposited between the seats, thus preventing the disc from closing. Incomplete previous closing allowed the fluid to impact onto the seal surfaces, eroding these. The valve has been used for line flushing, and therefore seats have been damaged by foreign material. For all the above cases it is absolutely necessary to disassemble the valve as soon as possible and proceed with an inspection of the internal parts in order to reduce further damage. 5.4 Jamming of valve along the stroke If a higher torque is required at some points along the stroke when opening/closing the valve, proceed as follows: Examine the stem and make sure that there is no picking-up in either the smooth or the threaded parts. Disassemble the valve, as a seizure may be starting to form between body guides and disc. 5.5 Problems relevant to motor operators For these problems, refer to the actuator instruction manual. Emerson reserves the right to change the contents without notice page 3

4 6. Disassembly Instructions Below are the procedures to follow to disassemble valves. Before starting any operation, it is important to: identify the problem clean the area around the valve that is to be disassembled arrange for a box and/or a pallet for all components arrange for a polyethylene sheet to protect all components and to avoid that any particles inadvertently enter the body. 1. Fully close valve. 2. Loosen and remove the nuts (26.1), remove the position indicator 3. Loosen and remove the nuts (9). 4. Using suitable lifting equipment, lift the handwheel/yoke assembly. 5. Loosen and remove the gland nuts (17), gland flange (16) and gland (15). 6. Remove safety ring (4). 7. Knock down the bonnet (2) with a soft-faced hammer to relieve the load on the segment ring (5), by pushing them outside through the four radial holes in the body. 8. Reassemble the safety ring and nuts (4). 9. Tighten the nuts (11) of the bonnet bolts (10) evenly, until the bonnet is lifted. Remove the ring (6) and the pressure seal gasket (7). 10. After the gasket has been removed, proceed by removing the bonnet (2) assembly with stem (20) and disc(28). Before starting disassembly it is very important to verify for your safety that: the line is not pressurized the line is at ambient temperature the line is drained all electrical supplies have been switched off and disconnected prior to dismantling the valve. Refer to figs. 3 and 4 7. Assembly Instructions Before starting assembly it is recommended to verify the following points: Remove any dirt or particles with a wire brush or abrasive cloth; remove any oil or grease with a suitable solvent, to avoid damage cause by foreign particles in particular on the sealing area. Never re-use the old gaskets, even though they seem to be in good shape. Verify that there are no scratches on the body sealing area. 1. Place the disc (28) on a clean flat surface, then fit the stem (20) into the disc. 2. Fit the disc nut (30) over the stem (20), screw into the disc (28) and then tighten. Ensure that the stem is free to move. Then tack weld the disc nut to the disc. 3. Fit the bonnet assembly with stem (20) and disc (28) into body (1). 4. Place a new pressure seal gasket on the bonnet. 5. Assemble the ring (6) and the segment rings (5). 6. Insert the safety ring (4) and tighten the nuts (10) to the torque values stated in table Fit the ground ring (13), a new gland packing (14), gland (15), gland flange (16) and gland nuts (17), and tighten these evenly. DO NOT over-tighten as this will cause high friction loads on the stem. 8. Using suitable lifting equipment, carefully lower the handwheel/yoke assembly onto the valve, taking care not to damage the yoke studs (8). Secure the assembly by cross-tightening the yoke nuts (9). 10. Fit the position indicator (25) 11. After the valve has been pressurized, verify that the nuts (9) are tightened by following the tightening torque values indicated in table 2. Emerson reserves the right to change the contents without notice page 4

5 8. Spare parts list Emerson guarantees the supply of any spare part for a period of at least ten years from the manufacturing date (month/year) indicated on the tag plate. The main objective in formulating a service parts inventory policy is the capability to provide prompt valve service, thus preventing extension of maintenance down time. To accomplish this, it is necessary to have the proper service parts immediately available for the optimum number of valves. This can be achieved at a minimum cost by defining the inventory on a frequency of need basis. To assist in reaching this objective, the field service and repair organization of Raimondi recommends following these guidelines in order to establish inventory levels: 1. Identify the total number of valves in service by size, type number, pressure/temperature class, tag number. 2. Identify the frequency of replacement tendency of specific parts: Class I Parts most frequently replaced. Class II Parts less frequently replaced, but critical in the event of an emergency requirement. Class III Parts seldom replaced Class IV Hardware (e.g. nuts, bolts, pins, cap components etc.) Class V Parts practically never requiring replacement 3. Operational reliability is defined as a probable percentage (%) of total, uninterrupted operational time that can be expected by stocking predetermined valve component classifications. Determine the operational reliability which is compatible with a specific company s operational objectives and service parts inventory investment policy. Then relate operational reliability to part classifications, which will satisfy that need. Guidelines are as follows: Parts classification Operational reliability Class I 70% Class I and II 85% Class I, II and III 95% Class I, II, III and IV 99% 4. Consult recommended spare parts list by valve type to determine quantity of parts valves to be covered by the inventory plan. 5. Select parts and specify quantities. Classification of spare parts Classification Item No. Description CLASS I 7 Pressure seal Parts most frequently replaced 14 Gasket CLASS II 20 Stem Parts less frequently replaced but 15 Gland critical in case of an emergency 28 Disc 30 Disc nut 33 Socket head screw CLASS III 25 Position indicator Parts seldom replaced 16 Gland flange CLASS IV 8 Body/yoke stud Hardware (e.g. nuts, studs, pins, etc.) 9 Body/yoke nut 10 Body/bonnet stud 11 Body/bonnet stud 18 Gland stud 17 Gland nut CLASS V Parts practically never requiring replacement Balance Emerson reserves the right to change the contents without notice page 5

6 9. Appendices The reference drawings are those relating to the supply only. The drawings published in this manual are typical drawings only and may not represent the valves supplied. Fig. 3 - Typical valve 51A 51B A By-pass Outlet Inlet Table 1 - Parts list Pos. Part name Material Pos. Part name Material Pos. Part name Material 1 Body A Body seat surface A 182 F6A 2 Bonnet A Yoke A St 35 4 Safety ring A Segment ring A Ring A Body/bonnet gasket Pure graphite 8 Body/bonnet bolts A 193 B7 9 Body/bonnet nuts A 194 2H 10 Nuts A 194 2H 11 Bolts A 193 B7 13 Ground ring A 182 F6A 14 Packing Pure graphite 15 Gland A 182 F6A 16 Gland flange A Gland nuts A 194 2H 18 Gland bolts A 193 B7 19 Gland gasket Graphite 20 Stem X35CrMo17 21 Yoke nut B 148 Gr. B 22 Bearings C. steel 23 Flange A Socket head screw Class Position indicator A Security pin Class Nut Class Lubricator C. steel 28 Disc A Disc surface A 182 F6A 30 Disc nut A 182 F6A 31 Cylinder A 182 F6A 32 O-ring Viton A-75 Sh.A 33 Socket head screw Stainless steel 35 Key AISI Stem key AISI Actuator 51 Stub PFE Nuts Extension Extension key AISI 4140 Emerson reserves the right to change the contents without notice page 6

7 Table 2 - Tightening torque values for bolts/screws Body/yoke - Bolts/screws: A 193 B7 Bonnet - Bolts/screws: A 193 B7 Ø Bolts/screws Torque values Ø Bolts/screws Torque values Kgm (Nm) Kgm (Nm) M12 5 (50) M12 1 (9) M16 10 (100) M16 2 (18) M20 17 (170) M20 3 (30) M22 29 (280) M22 5 (48) M24 43 (420) M24 7,5 (73) M30 61 (600) M30 11 (105) M33 86 (850) M33 15 (150) M (1100) M36 21 (205) Stem Gland bolts: A 193 B7 Diam. M16 M18 M20 M22 M24 M27 M30 M33 25,4 1,90 2,10 2,40 2,60 2,80 3,20 3,60 3,90 31,8 3,00 3,30 3,70 4,00 4,40 5,00 5,60 6,10 34,9 3,30 3,60 4,00 4,40 4,80 5,40 6,00 6,60 44,5 4,90 5,50 6,10 6,60 7,30 8,20 9,10 10,00 50,8 6,60 7,40 8,20 8,80 9,70 11,00 12,20 13,40 57,2 8,60 9,60 10,60 11,40 12,60 14,20 15,80 17,30 63,5 9,40 10,40 11,50 12,50 13,70 15,50 17,30 18,80 69,8 10,10 11,30 12,50 13,50 14,90 16,80 18,70 20,40 76,2 12,70 14,10 15,60 16,80 18,50 21,00 23,30 25,40 82,5 13,90 15,50 17,10 18,50 20,40 23,00 25,60 28,00 95,3 15,30 17,00 18,80 20,30 22,40 25,30 28,10 30,70 Select the constant in relation to stem diameter and packing bolt size In order to obtain the packing bolt torque in Nm multiply the selected constant for pressure in MPa Example Valve under pressure of 24 MPa with steam diameter equal to 44,5 mm and packing bolt size equal to M16 a. Constant is equal to 4,9 b. Packing bolts torque is equal to 4,9 x 24 = 117,6 Nm Table 3 Suggested greases Manufacturers Suggested Greases for bearings Agip GRMUEP2 API PGX2 BP Grease LTX 2 Esso Beacon 2 Fina Finagrease HP Finagrease EPL2 Mobil Mobilux EP2 Q8 Q8 Rembrandt EP2 Shell Alvania R2 Supergrease A Texaco Multifak EP2 Grease L2 Total Multis EP2 Multis 2 Viscol Signal Rolsfer 2 Apply Molykote to the stem threads. All other bolts and nuts are assembled with usual lubricant or Molykote. Emerson reserves the right to change the contents without notice page 7