Uniflex-stow remote valve operating systems

Transcription

1 Flexible shaft system 1 INTRODUCTION The purpose is to provide the user with basic information for the specification, installation, operation, maintenance, repair and parts identification of the Uniflex-stow rotary flexible shaft system. Remote mechanical systems for the operation of valves are to be fitted where: a. The standard lever or handwheel cannot be fitted or operated due to the restricted space or the position in which the valve has to be sited. b. A requirement for operation from more than one position is specified in the building specification. c. The valve is located in a physically difficult to access position or hazardous/restricted environment d. Where local operation raises a safety issue e. When manual mechanical systems are required for reasons of back-up (redundancy and diversity) Selection of a suitable Uniflex-stow solution The Uniflex-stow range features three systems; Uniflex-stow flexible shaft system with integrated gearing Uniflex-stow flexible shaft Uniflex-stow rigid rod In general Uniflex-stow flexible shaft systems should be selected for longer and/or more complex routings. If, when considering a rigid rod installation, the routing is longer than 20 ft and/or, regardless of length, has more than two 90 degree gearboxes then select a flexible shaft system. 1

2 2 CAPACITY INFORMATION The capacity below and efficiency (Appendix, Table 1&II) determine system capacity 3 FUNCTIONAL DESCRIPTION The rotary flexible shafting is designed to receive input torque (rotary motion by manually turning a handwheel or tee wrench) at the operator station and to effectively deliver this torque (rotary motion) to a remotely located valve/valve gearbox. The torque moves through a single flexible inner core rotating in a conduit (casing) between the two stations. The core is directly connected at both ends and operates in a rotary motion. 4 PHYSICAL DESCRIPTION The rotary flexible shafting uses three basic assemblies: a) The remote operator b) The flexible shaft c) The valve or valve gearbox coupling In addition, DG ENERGY can supply a range of valve gearboxes to suit any system requirement. REMOTE OPERATOR, and HANDWHEEL The handwheel or tee wrench of remote operator or deck box connects directly to an input spindle. The input spindle of the remote operator has a tapered square which will accept a handwheel. The proper selection of handwheel size can be determined by using calculator and applicable tables. The inner core assembly of the flexible shaft is drilled and pinned to the output spindle. Then the D.C. terminal, or direct connect terminal, which is part of the rotary flexible shafting casing assembly, is connected to the hub using three washerhead handscrews. Penetrating a Shield Wall or Floor There are several types of shield wall and floor penetrations that are installed by utilizing either the cast-in-place or grout-in-place construction methods. 2

3 Cast-In-Place: This method is recommended when schedules permit advance planning of the penetration location. The castin-place type housing is attached to the concrete forms and becomes a permanent part of the wall at the time the concrete is poured. Grout-In-Place: This method is generally specified when the exact number and location of penetrations is not known prior to the pouring of the shielding wall. Usually, several possible locations are selected and six (6) inch diameter, schedule 40 pipe is embedded when the wall (or floor) is poured. Later, the grout-in-place type housing can be inserted into one of the pipes and set in place with high- density grout. An alternate method is to core-drill a hole through the shield wall, insert the grout-in-place type housing and set in place with high-density grout. Both types of shield wall and floor housings are designed with a compensating spindle length that will accommodate plus or minus one-half (1/2) inch from nominal wall thickness. The shielded penetration is 100% serviceable from the cold side of the shield wall, including seal replacement. Spindle bearings on the hot side of the wall are oil- impregnated sintered bronze and highly resistant to the effects of radiation. Operating Stations for Shielded Penetrations The addition of a Stow Torque-Limiting Clutch to an operating station (plain or indicating) permits the controlled operation of small plug, ball, diaphragm or instrumentation valves without the attendant concern for over-torquing valve stems or seats. Stow s torque limiting clutch can be easily set to any torque within its range of inch-pounds after installation into a system. The clutch is permanently lubricated and has a repetitive accuracy of approximately 95 h over its full operating range. Operating Stations for Nonshielded Penetrations Handwheels mounted on torque transmission spindles, wall terminals and floor stands make up the basic operating stations. 3

4 A 90 gearbox (with indicator) operating station is available to bring high or low wall penetrations to a comfortable chest-high operating height. Stuffing boxes are installed where the rotary flexible shafting penetrates compartment bulkheads or decks. Stuffing boxes serve to maintain the watertight integrity of the bulkhead. INNER CORE AND CASING The inner core and casing (rotary flexible shaft assembly) is the driving link between the remote operator or deck box assembly and the valve. The inner core is supplied with an end fitting that is attached to the output spindle (via a terminal coupling) of the remote operator assembly and the input spindle of the valve or valve gearbox (via a terminal coupling). The casing assembly is connected to the hub of mating assemblies using a direct connect terminal or terminal coupling. The direct connect terminal or terminal coupling produces a watertight seal as well as a direct connection between casing and hub of remote operator, deck box and valve or valve gearbox. The rotary flexible shaft assembly (inner core and casing) is supported by clamps and mounting brackets which are bolted or tack welded to the rigid structures. Clamps secure the rotary flexible shafting as close to remote operator or deck box and valve as possible. Clamps are used throughout the rotary flexible shafting run at approximately five foot intervals where convenient. Where radial bends are installed in the rotary flexible shafting run, they are to be made as large as possible (see Table x for details) to minimize frictional loading. Clamps are to be located at the beginning and end of a radial bend as a minimum, also in the middle of the bend, if possible. The inner core is precision manufactured using a high tensile carbon or stainless steel wire wound in layers of opposing directions upon a single center wire. The casing that supports the core during operation is manufactured from galvanized steel and other corrosion resistant steel chosen to withstand the effects of dust, oil, moisture, abrasion and temperature extremes; such as a flash fire or other severe conditions. VALVE INTERFACE COMPONENTS The connection to the valve or valve gearbox is made with both rising and non-rising valve couplings and terminal couplings (SF type). When the valve is positioned in an accessible location, then a quick-disconnect valve coupling should be installed at the valve location. The quick disconnect coupling allows the valve to be easily disconnected from the remote mechanical valve actuator system so that the valve may be locally operated at the valve location. 4

5 Connection is made directly to the existing valve handwheel using a valve coupling. The valve coupling is secured using U bolts. If connection is be made directly to the valve or valve gearbox stem then a SF type coupling is used. 5. CALCULATION OF LENGTH Use the above as an aid. However, the flexible length does not need to be precise but it must be long enough to connect each end. An assessment of length up to 10% longer than precisely required is usually workable. It is recommended that lengths be measured on site where possible. Tip: using a flexible plastic hose pipe is an effective way of assessing the required length. 5

6 6. ASSEMBLY TOOLS Rotary flexible shafting (core and casing) comes completely assembled. Simple tools such as hand drills, hammers, and screwdrivers are used to connect the rotary flexible shafting assembly to remote operators, deck boxes and valve station actuators. 7. SYSTEM INSTALLATION The remote operator or deck box and valve coupling are installed first. Then these components are connected with the rotary flexible shaft assembly. The approximate length of the flexible shafting should be calculated before ordering. This allows the rotary flexible shaft assembly to be preassembled. Once the system components are attached to each other; the system is complete. The casing should be installed using uniform bend radii to optimize efficiency of the system. Once the system has been secured using proper clamping techniques, the system is then complete. Once the system is completely installed, it may be desirable for future reference to determine and record the frictional load of the system. This is the torque required to operate the system with the valve fully disconnected. This is an example of a typical installation procedure ; 1. Mount remote operator or deck box assembly or floor/wall penetration. Ensure in closed indicator position. 2. Attach and route flexible shafting assembly. Attach using valve couplings to handwheel or SF type couplings or adapter. 3. Attach brackets, clamps, and stuffing box where required. 4. If installing valve gearbox, fit to valve. 5. Position valve and indicator mechanism in desired position ie; cycle valve closed, and then position indicator to read closed position 6. Connect valve coupling to existing handwheel (secure with U bolts). Ensure position is central. When connecting with a rising handwheel valve coupling, position valve handwheel at its lowest point (closed). or Connect to valve stem or valve gearbox stem directly using an SF coupling. 7. Cycle system to fully open position and record open position. Cycle system to fully closed position and record closed position. On operator indicate open & closed. 8. Once system is fully installed and operational, open and close system with a torque wrench and record operational torque. Mark this number on system tag for future reference. 6

7 8. CHARACTERISTICS The functional characteristics of the rotary flexible shafting and associated components are as follows: (1) Shock : System meets requirements of MIL-S 901C Class 1. (3) Maximum Torque Input to valve or valve gearbox: 250 ft lbs (dependant on shaft diameter) (4) Maximum Capacity at Valve Stem : depends on length, bends and (if required) valve gearbox (5) Operator Directional Rotation vs Valve Directional Rotation : Same Direction. (6) Vibration : System Meets Requirements of MIL-STD-167 (8) Leakage (Immersion) : The system will penetrate floors/decks and walls/bulkheads. Components shall maintain watertight integrity per MIL-STD-810E Section (9) Corrosion : Exposed components may be painted or made from non corrosive materials. (10) Maintenance : Shall not require scheduled maintenance beyond outlined in this section. (11) Clamp cable approximately every 5 ft. (12) The system is sized so that one man can operate and cannot overload the system using a handwheel. 9. SPECIFICATION Data required for the proper specification of a remote operating system; Not all data is essential. Minimum data required is valve type, handwheel or torque, routed length and estimated bends. 7

8 Calculations for operating force, system deflection and shear pin The operating force is the force necessary to cause operation of the valve or valve gearbox by the Uniflex-stow system. The system deflection can be defined as the amount of motion applied to a hand wheel or tee wrench before actual output motion occurs on the valve or device to be operated. This can also be referred to as lost motion. Recommended not to exceed 180 degrees. There are three major variables that will define the amount of operating force and the amount of deflection in a system. They are: 1.) Maximum anticipated valve torque (max valve operating torque +25% degredation factor. 2.) Total degrees of bends in system. 3.) Flexible shaft length. Example: Maximum valve operating torque (or required input to existing valve gearbox) value of 60 ft. Lbs. (+ 25% degredation)= 75ft. Lbs., Flexible shaft length will be 25 feet Total degrees of bend will be ) Determine input torque to flexible shaft: Assuming the valve operating torque is 75 ft lbs (including 25% for degradation) a.) Torque reduction caused by 180 degree bends (appendix 1, table I : 94% efficient): 75 ft lb 0.94 = 79.8 ftlbs b.) Torque reduction caused by 25 foot length (appendix 1, table II : 70 % efficient): 79.8 ft. Lbs = 114 ft.lbs. Required input torque to the flexible shaft. c.) Torque reduction caused by remote operator (appendix1, table III: 98% efficient): 114 ft lbs 0.98 = 116 ft lbs. Required input to handwheel Using the table in para.2 above the flexible shaft selection is 1 ¼. 8

9 2.) Determine the handwheel and consideration of gearing Using table IV in appendix, the recommended handwheel is 35 diameter. If this is too large then a valve gearbox should be considered. DG ENERGY can supply a large range of 3rd Party gearboxes. These will be selected to optimize the overall system performance. Connection of the flexible shaft to the gearbox is usually made using an SF type coupling or flanged adapter. Geared example based on data above. Valve : Multi-turn type with 10 turns to open/close Select gearbox with 4:1 ratio (Mechanical advantage (MA) of 3). Therefore; Input torque is now 116 ftlbs 3 (MA) = 38.6 ft lbs (39 ftlbs) Handwheel is now 12 diameter Number of turns to open/close = 40 Alternatively, by incorporating a gearbox we can consider reducing the Uniflex-stow shaft diameter. The input torque to the valve gearbox is now 39 ft lbs and using the table in para. 2 above the flexible shaft selection is ¾. 3.) Determine maximum system deflection Recommended not to exceed 180 degrees. System deflection is calculated using the average of the input and output torques of the flexible shaft, multiplied by the length of the flexible shaft, multiplied by the deflection per ft. at average torque. a.) Average torque: ( ft.lbs.) 2 = 95.5 ft.lbs. b.) Deflection per ft at avg. torque : 95.5/160 x 5 = 3 degree per ft (ref. table para. 2) c.) Deflection: 25 ft. X 3 degree per ft = 75 A software calculator for the above calculator is available from DG ENERGY on request. 9

10 10. MAINTENANCE The purpose of maintenance is to insure that the rotary flexible shafting system continues to operate at optimum levels. The following schedule of maintenance must be performed on a regular basis in order to keep the rotary flexible shafting mechanical actuator system in normal operating condition. INNER CORE AND OUTER CASING Inspect entire run of rotary flexible shafting for damaged casing which could affect system operation. Replace damaged casing if it cannot be repaired. If system shows appreciable increases in torque, then inner core should be removed and inspected. If no damage is found, regrease inner core and insert into outer casing. Retest if the increased torque is still present; remote operator or valve station actuator will have to be replaced. ROTARY FLEXIBLE SHAFTING SUPPORT CLAMPS Inspect entire run of flexible shafting for correct location, required number, and type of all support clamps. Replace all missing clamps and tighten all loose clamps. Visually inspect flexible shaft run when system is under torque to look for any undesirable bends or helix. MOUNTING Inspect mounting brackets, flanges, actuator housing, and mounting to handwheel for missing and loose bolts. Replace missing bolts and tighten all loose bolts. TROUBLESHOOTING Troubleshooting of the rotary flexible shafting should be performed by personnel familiar with the system. ISOLATION OF PROBLEM If during normal use of the rotary flexible shafting system there are no indications that there has been a significant increase in applied torque, then system is in good working order. If an appreciable increase in torque is noticed, make the following check: (I) Completely disengage the rotary flexible shafting mechanical actuator system from the valve coupling. This can be accomplished through the use of the quick disconnect if installed. If no quick-disconnect has been installed, then valve coupling can be unbolted from handwheel of valve or SF coupling unpinned. (2) While the valve is completely disconnected, operate the rotary flexible shafting mechanical actuator. It should be free from binding through its complete operation in both directions. 10

11 (3) If torque is considered too high (compare with initial recorded system friction load, if available) and system appears to be undamaged, regrease. If inner core appears damaged, replacement of the complete flexible shafting assembly may be necessary. If regreasing flexible shafting will not return system to an acceptable condition, test the remote operator or deck box with flexible shafting disconnected. If not free to operate the unit must be replaced. If acceptable, then test valve station actuator with flexible shafting removed. If all tests do not reveal a problem, consult DG ENERGY customer service. 11

12 DISASSEMBLE The system once installed may be disassembled in the reverse order of Installation Procedure. Individual components are made of non-corrosive material and do not need to be disassembled. Note: Do not disassemble Valve gearbox. The gearbox is composed of many small precision components which could be easily lost or damaged. Improper disassembly could cause a loss in efficiency. TESTING AFTER RE-ASSEMBLY Units should be tested for ease of operation. Torque values should be taken and compared to values taken when units were originally installed. INSPECTION Systems should be inspected and operated on a regular basis to insure proper working order. CLEANING Rotary flexible shafting system is made of noncorrosive materials and may be cleaned with any common solvents such as soap and water or if needed any common degreasing agents. LUBRICATION Systems should be lubricated once during assembly and do not need to be re-greased. Systems are supplied with grease fitting in case a situation occurs in which lubrication must be added. Standard grease used is; Aeroshell 5 for flex shaft assembly; or where there is exposure to radiation; Fosythe MOV Long Life Valve Grease, NLGI-2. Note: Do not over lubricate flexible shaft since it may cause binding. REPAIR If repairs are needed, spare parts may be purchased from DG ENERGY, Delmont PA,

13 11. COMPONENT DETAILS AND DRAWINGS Please consult the latest Uniflex-stow catalog for a complete list of system components, general dimensions and materials 12. APPENDIX 13

14 Table III - Component Efficiency Item Description Supplemental Information Item Part Number Efficiency Factor Double Universal Joint Offset Angle 0 to Double Universal Joint Offset Angle 6 to Valve Station Actuator (VSA) Ratio = 6: Valve Station Actuator (VSA) Ratio = 11: Valve Station Actuator (VSA) Ratio = 17: Valve Station Actuator (VSA) Ratio = 25: Valve Station Actuator (VSA) Ratio = 43: Valve Station Actuator (VSA) Ratio = 2.8: Intermediate Operator Ratio = 1: Remote Operator Ratio = 1: Gear Box Remote Operator Ratio = 1: Deck Box Remote Operator (Without Weld Sleeve) Ratio = 1: Deck Box Remote Operator (With Stl Weld Sleeve) Ratio = 1: Deck Box Remote Operator (With SST Weld Sleeve) Ratio = 1: Deck Box Remote Operator (With Brz Bolt Sleeve) Ratio = 1: Deck Box Remote Operator (With Alum Weld Sleeve) Ratio = 1: Valve Station Actuator (Space Limited) Ratio = 4:1 (use with below Operators) Operator, Remote, 10 Turns Ind. Ratio = 1:1 (use with ) Operator, Remote, 68 Turns Ind. Ratio = 1:1 (use with ) Operator, Remote, 40 Turns Ind. Ratio = 1:1 (use with ) Operator, Remote, 90 Gear Box, Weld, 10 Turns Ind. Ratio = 1:1 (use with ) Operator, Remote, 90 Gear Box, Weld, 40 Turns Ind. Ratio = 1:1 (use with ) Operator, Remote, 90 Gear Box, Weld, 68 Turns Ind. Ratio = 1:1 (use with ) Operator, Remote, 90 Gear Box, Weld, 22 Turns Ind. Ratio = 1:1 (use with ) Operator, Remote, 90 Gear Box, Bolt Ratio = 1:1 (use with )

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