Emerson CROSBY STYLE HC ISOFLEX, CROSBY STYLE HCA ISOFLEX Installation, Maintenance And Adjustment Instructions

CROSBY® STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Before installation these instructions must be read fully and understood
TABLE OF CONTENTS
1. Style HC/HCA ISOFLEX - parts ..................... 2
2. Introduction ................................................... 3
3. Description of safety valve ............................ 4
4. Storage ........................................................... 4
5. Installation ..................................................... 5
6. Hydrostatic testing ........................................ 6
7. Operation ....................................................... 9
Safety precautions
Proper handling, storage, installation, maintenance and operation is essential to the safe and reliable functioning of any pressure relief product. Precautionary statements in the form of warnings, cautions and notes are used throughout this instruction to emphasize important and critical factors where applicable.
Examples: WARNING
An operating procedure or practice which, if not observed strictly, may result in injury to personnel or loss of life.
CAUTION
An operating procedure or practice which, if not observed strictly, may result in damage to or destruction of equipment.
NOTE
An operating procedure or condition which is highlighted, underlined or printed in bold type for emphasis. These precautionary statements are by no means exhaustive. Emerson cannot be expected to know, evaluate and advise customers of all conceivable ways in which tasks might be performed, or of the possible hazardous consequences of each way.
Consequently, Emerson has not included such comprehensive evaluation and disclaims liability for work performed by other than Emerson personnel. All personnel working with Crosby products should be trained adequately and be thoroughly familiar with the contents of this manual. Emerson cannot evaluate all conditions that might injure personnel or damage equipment. However, Emerson does offer the following general safety precautions:
• Hearing and eye protection should be used when working on a valve which is under pressure.
• Never strike a valve which is under pressure. Premature actuation can result.
• Never stand in front of the discharge outlet of a pressure relief valve which is under pressure.
Always approach and use any pressure relief valvewith great care.
Often, the safety of lives and property depends on the proper operation of the safety valves. Consequently, the valves should be kept clean and should be tested periodically and reconditioned to make sure theyfunctionproperly.
WARNING
Suitability of the material and product for the use contemplated by the buyer is the sole responsibility of the buyer. Also storage, installation and proper use and application are the sole responsibility of the purchaser. Emerson disclaims any and all liability arising out of same. Any installation, maintenance, adjustment, repair and testing performed on safety relief valves should be done in accordance with the requirements of all applicable codes and standards under which those performing such work should maintain proper authorization through appropriate governing authorities. No repair, assembly and test work done by other than Emerson shall be covered by the warranty extended by Emerson to its customers.You assume full responsibility for your work. In maintaining and repairing Crosby products, you should use only parts manufactured by Emerson. Call your nearest Emerson sales office or our factory for a service engineer should you wish assistance with your field needs.
Engineering Doc. #IS-V3147A
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CROSBY® STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
FIGURE 1 - STYLE HC ISOFLEX SAFETY VALVE
PARTS LIST
Part Part name Spare parts*
1A Body 1B Nozzle 3 Nozzle ring 3 4 Nozzle ring set screw 5 Disc insert 1 6 Disc holder 2 7 Disc holder retaining nut 8 Disc holder retaining cotter 1 9 Guide 3 10 Guide ring 3 11 Guide ring set screw 12A Spindle point 3 12B Spindle rod 3 12C Spindle rod pin 3 13 Bonnet 14 Bonnet stud 15 Bonnet stud nut 16 Spring 3 17 Bottom spring washer 3 18A Top spring washer 3 18B Bearing pin 3 18C Locking pin 3 19 Bearing adapter 20 Bearing 21A Adjusting bolt 21B Adjusting bolt bearing 22 Adjusting bolt nut 23 Spindle nut 24 Spindle nut cotter 1 25 Cap 26 Cap set screw 27 Lever 28 Lever pin 29 Lever pin cotter 1 30 Forked lever 31 Forked lever pin 32 Forked lever pin cotter 1 34 Test clamp 36 Test rod 37 Seal and wire 38 Protective hood 39 Drain plug 40 Hydro test plug assembly 41 Nameplate 42 Drive screw 43** Cooling spool 44** Cooling spool stud 45** Cooling spool stud nut
NOTES
* Spare parts designation (see notes 1, 2, 3 in Section 2) ** For Crosby Style HCA ISOFLEX only
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CROSBY® STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
FIGURE 2 - STYLE HCA ISOFLEX SAFETY VALVE
2 INTRODUCTION
Crosby Style HC and HCA ISOFLEX safety valves have been selected because of their performance features, reliability and ease ofmaintenance. This manual contains information on installation, hydrostatic testing, field testing and adjustments and maintenance of these valves. It is specific to the Isoflex design K through M
orifice sizes. Adherence to the
2
installation and maintenance procedures specified in this manual will provide the utmost in safety, a minimum of maintenance and a long service life. Style HC is a high capacity reaction type safety valve designed for saturated and superheated steam applications to temperatures of 750°F. Crosby Style HCA is a high temperature version of the Style HC, with an alloy steel construction suitable to temperatures upto1020°F. TypicallyStyle HCA valves are used for superheaters and reheater outlets.
DetailsofStyle HC and HCA safety valves, materials of construction, sizes, pressure­temperature ratings, dimensions, weights and certified capacities are available on request. No special tools are necessary for the maintenance of Style HC and HCA safetyvalves. However, tools and equipment are available to ease disassembly and on site testing of the valves. Such tools and equipment include the hydraulic set pressure device, the air set pressure device (see Figure 15) and the hydraulic jacking device (see Figure 14). Detailed instructions on their use can be found in instructions I-11288, T-1652 and I-1167 respectively. Whenever Style HC/HCA safety valve parts names are used in this manual, parts numbers in parenthesis follow. The parts numbers are an aid to identifying the parts in Figures 1 and 2 and the correlating parts list.
NOTES
1. Consumable spare parts: valve parts which should be replaced as part of any disassembly, and discs and disc inserts which must be replaced if seats are damaged.
2. Repair spare parts: valve parts exposed to wear and/or corrosion during normal operation. They are in fluid flow paths and may require replacement as part of any repair.
3. Insurance spare parts: valve parts exposed to process or environmental wear and/or corrosion and may require replacement as part of a majorrepair.
Emerson recommends that sufficient inventory of spare parts be maintained to support process requirements. Always be sure to use genuine Emerson parts to ensure continued product performance and warranty.
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CROSBY® STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Crosby Style HC/HCA ISOFLEX nameplate
(With sample information for illustrative purposes only)
Ordering spare parts
When ordering spare parts, the valve size, style and shop number and/or serial number should be given together with set pressure, part name and reference number. The valve assembly number is shown on the valve nameplate as 'Shop number'. Spare parts may be ordered from any Emerson sales office orrepresentative.
3 DESCRIPTION OF SAFETY VALVES
Crosby Style HC/HCA safety valves are shown in Figures 1 and 2. These drawings illustrate the safety valves assembled in cross-section, and cover the essential elements of the valves. Approved drawings supplied with the valves should be used when installation and/or specific information is required. Inside the body (1A) is housed the upper portion of the nozzle (1B), nozzle ring (3), and the guide ring (10). The disc insert (5) is held in place in the disc holder (6) by the spindle and disc holder retainer nut (7). The nozzle ring and adjusting rings are held in place by the nozzle ring set screw (4) and the guide ring set screw(11), which are threaded into the body.
The guide (9) is retained between the body (1A) and the bonnet (13) by the bonnet studs (14) and the bonnet studs nuts (15). In the case of Style HCA valves, a cooling spool (43) is placed between the body and bonnet to protect the spring from exposure to extreme temperatures. The bonnet (13) contains the spring (16), spring washers (17 and 18) and the spindle assembly(12). The spindle point is held in compression between the back face of the disc insert (5) and the bottom spring washer. The spring is compressed between the stationary point of contact with the spindle and the adjusting bolt (21A) atop the valve bonnet. The adjusting bolt (21A) is locked in place by the adjusting bolt nut (22) on top of the bonnet and within the cap assembly. A means of manual lifting is provided by the lever (27), lever pin (28), forked lever (30), forked lever pin (31) and the spindle nut (23).
4 STORAGE
Often, safety valves are on the job site months before they are installed. Unless they are stored properly and protected, their performance may be affected seriously. Rough handling may damage flanges or cause misalignment of the parts. It is best to leave the safety valves in their shipment cases and store them in a dry place under cover until they are tobe installed.
FIGURE 3 - VALVE BODY AS SHIPPED
TOP VIEW - BODY
HYDRO COMPONENTS (see note 1, page 5)
FIGURE 4 - VALVE SUPERSTRUCTURE AS SHIPPED
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CROSBY® STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Factory preparation of welded inlet valves forshipment
All Crosby Style HC and HCA welded inlet safety valves are equipped with hydrostatic test plugs and shipped in two parts: valve body and valve superstructure. This makes handling easier for installation welding (seeFigures3and 4). The welded inlet Style HC and HCA safety valves are specially prepared for shipment fromthe factory. After the safety valve is tested as a complete assembly for set pressure and tightness, the spring set compression is held by spacer blocks under the bottom spring washer as illustrated in Figure 4. The safety valve superstructure is then removed from the valve body. The two portions are boxed and shipped separately. Each portion, ready for shipment, is illustrated in Figures 3 and 4. Figure 3 shows the safety valve body as shipped to the installation site. It is tagged as follows:
• Install and/or weld in place as required
• Prepare for hydrostatic test. See instruction Hydrostatic plug in place
• Install O-ring and backup ring prior to hydrostatic test.
Figure 4 shows the safety valve superstructure as shipped to the installation site. It is boxed separately from the valve body and is tagged asfollows:
• Hold for assembly after hydrostatic test.
5 INSTALLATION
Inlet piping
Many safety valves are damaged when first placed in service because of failure to clean the connections properly before installation. The safety valve inlet, the vessel and the line on which the safety valve is mounted must be cleaned thoroughly of all foreign matter. Safety valves should be mounted in a vertical position, directly on the pressure vessel. The ASME boiler and pressure vessel code limits the distance between the safety valve inlet and the boiler to the length of a standard tee fitting. The nozzle should have a well-rounded approach that provides smooth, unobstructed flow between the vessel and the safety valve. A safety valve should never be installed on a fitting having an inside diameter smaller than the inlet connection of the valve. Such restriction of flow can cause faulty valveoperation. Inlet piping (nozzles) must be designed to withstand the total resultant forces due to the safety valve discharging at the maximum accumulated pressure and the expected piping loads. The precise nature of the loading and the resulting stresses will depend on the configuration of the safety valve and the discharge piping. Determination of outlet reaction forces is the responsibility of the designer of the vessel and/or piping.
Welding of welded inlet valve body to boiler
Welded inlet safety valve bodies should be welded to the boiler in accordance with applicable Code requirements. The protective cover (Figure 3) should be left in place until ready for the hydrostatic test of the unit. If visual inspection is necessary, the protective cover may be removed, but should be replaced.
NOTES
Note 1 to Figure 3
Delivered with the body and packaged in small bag are the following:
• One O-ring (for hydrostatic test)
• One backup ring (for hydrostatic test)
• One hydrostatic test plug pin
Note 2 to Figure 4
Delivered with the superstructure and packaged in a small box are the following:
• Valve nozzle ring*
• Valve nozzle ring set screw*
• Valve guide ring set screw*
• Seal wires
* Marked with valve identification number.
NOTE
When the above parts are removed from their boxes, be sure that the identification of parts to valve number is maintained and that the parts are stored to facilitate later recovery for assembly.
Outlet piping
Discharge piping should be simple and direct. Back pressures built up by discharge flow affect the operation of safety valves. Where possible, a short vertical pipe connected through a long radius elbow discharging directly into the atmosphere is the most desirable type of outlet piping. Discharge piping should not impose any loading on the safety valve. Excessive discharge piping loads may cause seat leakage or faulty valve operation. The inside diameter of the discharge pipe must never be less than that of the safety valve outlet. Valve effluent must discharge to a safe disposalarea. Safety valve bodies have pipe thread openings for drains. These should be connected to prevent any accumulation of fluid in the valve body. In addition, discharge piping also should be drained to prevent any accumulation of fluid. Care must be taken to ensure that the drains are directed or piped to a safe disposal area.
5
CROSBY® STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
6 HYDROSTATIC TESTING
General information
Depending on the type of inlet, hydrostatic testing of safety valves may be carried out by one of three means: blank flanges, test plugs or test gags. In all cases, hydrostatic test pressure must be limited to 1½ times the nameplate set pressure of the valve.
CAUTION
Additionally, hydrostatic test pressure must be limited to 10% above nameplate set pressure when a test gag is used.
Welded inlet safety valves
All Style HC/HCA welded inlet safety valves are prepared for shipment from the factory with hydrostatic test plugs, as detailed in Section 4 ­paragraph 'Factory preparation of welded inlet valves for shipment' and Figure 3. Hydrostatic tests of these valves shall be conducted using hydrostatic test plugs as detailed in paragraph below 'Hydrostatic testing using hydrostatic test plugs'.
Flanged inlet safety valves
Flanged inlet safety valves should not be installed for hydrostatic testing. Blank flanges should be used instead of gagging the safety valves. This prevents possible damage to the safety valves due to excessive tightening of the gag screws or leakage during hydrostatic test which may result in costly repairs. Blank flanges must be removed and the safety valve reinstalled before the vessel isplacedinservice. If blank flanges are not used and the safety valves are to be installed for hydrostatic tests, Emerson recommends that hydrostatic test plugs be used for hydrostatic test. The detailed procedure is outlined in the paragraph following. Hydrostatic test plugs for flanged valves are optional equipment and are providedonly when ordered.
Remove the protective cover from the valve
body. Unscrew the cap from the nozzle. Remove the test plug from the nozzle bore.
• Preparation for hydrostatic testing ­Flanged inlet safety valves
Flanged inlet safety valves are shipped
from the factory fully assembled. To use the hydrostatic test plug, the valve must be disassembled according to Section 9 ­paragraph 'Disassembly retaining spring compression'.
• Installation of hydrostatic test plug (seeFigure 3)
Inspect the hydrostatic test plug O-ring
groove.
Note: make sure the groove in the plug
isclean.
Install the O-ring and backup ring in the
testplug groove.
CAUTION
Be sure the test plug is seated on the 45° angleonthe nozzle inside diameter.
Replace the test plug in the nozzle bore. Place the test plug cap over the plug and
screwit down hand-tight.
CAUTION
Make sure the cap has hand-tight contact with the plug. Make sure there is enough thread engagement of the cap onto the nozzle.
Install the test plug pin. The valve is now ready for hydrostatic test.
• Hydrostatic test
After the above preparation, the safety valve
is ready for hydrostatic test. Observations should be made at the start of the test to confirm that the O-rings have been installed properly and there is no leakage when pressure is applied.
To aid removal, place the hydrostatic test
plug pin in the hole in the plug extension. Unscrew the cap, which will engage the plug pin and exert an upward force as the cap is turned, thus lifting the plug. Remove from thevalvenozzle.
Clean the nozzle bore and seat and inspect
the seating surface. If seating surfaces are damaged, repair according to the directions in Section 9 - paragraph 'Repair procedure'.
Assemble the valves according to the
instructions in Section 6 - paragraph 'Initialsafety valve assembly'.
Contact Emerson field service for service
equipment (see Section 12 - paragraph 'Service equipment available').
Hydrostatic testing using hydrostatic testplugs
Before imposing the hydrostatic test pressure on the vessel or system, perform the following operations:
CAUTION
Before hydrostatic testing, the O-ring and backup ring must be installed.
• Preparation for hydrostatic testing ­Weldedinlet safety valves
The O-ring, backup ring and the test plug
pin are shipped in a box attached to the superstructure (see Figure 3). The contents ofthe box are marked for identification.
To install the O-ring and backup ring refer
toFigure 3.
CAUTION
Tightening of the cap will not reduce leakage. If leakage is evident, remove all pressure from the vessel or system. Replace the O-ring and thebackup ring.
WARNING
Do not try to assemble the valve or remove the steel blocks from under the bottom spring washerwithout use of proper servicing and assembly equipment.
• Assembly of valve After completion of the hydrostatic test,
remove the hydrostatic test plug from thenozzle.
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