S DOUBLE VALVES with L-G MONITOR
Contents
1. p cs cl c error Il x 6 ty i 15 2 1 B B i SB 10 Zu 5 U l J Figure 3 Valve in Faulted Condition 2 2012 ROSS CONTROLS All Rights Reserved VALVE CONDITIONS RESULTING FROM A MALFUNCTION At the same time a monitoring air signal goes via passage 6 only to the right end of spool C When the difference in pressure at the ends of the spool exceeds 20 psi 1 5 bar the spool is shifted In this case the spool is shifted to the left see Figure 5 The spring loaded lockout pin K drops into lockout groove 8 so that the spool is F 16 held in its shifted position Pilot supply air from passage 4 is then diverted around the spool and out to atmosphere via bleed vent 12 Simultaneously air in the pilot 9 air passage 9 is vented to atmosphere via bleed vent 13 This exhausting of pilot air allows the main valve elements A and B to return to their deactuated positions and a L prevents further actuation The valve is now locked out of operation and cannot be T N14 actuated until the L G monitor is reset Note that the lockout conditions described E here also hold true when the L G spool is shifted to the right 8 K C Lockout Signal Port Port 16 Figure 4 can be connected to a pressure indicator to show when a lockout has occurred During normal operation the pr2. which are warranted for a period of seven years from the date of purchase to be free of defects in material and workmanship ROSS obligation under this warranty is limited to repair or replacement of the product or refund of the purchase price paid solely at the discretion of ROSS and provided such product is returned to ROSS freight prepaid and upon examination by ROSS is found to be defective This warranty becomes void in the event that product has been subject to misuse misapplication improper maintenance modification or tampering THE WARRANTY EXPRESSED ABOVE IS IN LIEU OF AND EXCLUSIVE OF ALL OTHER WARRANTIES AND ROSS EXPRESSLY DISCLAIMS ALL OTHER WARRANTIES EITHER EXPRESSED OR IMPLIED WITH RESPECT TO MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ROSS MAKES NO WARRANTY WITH RESPECT TO ITS PRODUCTS MEETING THE PROVISIONS OF ANY GOVERNMENTAL OCCUPATIONAL SAFETY AND OR HEALTH LAWS OR REGULATIONS IN NO EVENT IS ROSS LIABLE TO PURCHASER USER THEIR EMPLOYEES OR OTHERS FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES WHICH MAY RESULT FROM A BREACH OF THE WARRANTY DESCRIBED ABOVE OR THE USE OR MISUSE OF THE PRODUCTS NO STATEMENT OF ANY REPRESENTATIVE OR EMPLOYEE OF ROSS MAY EXTEND THE LIABILITY OF ROSS AS SET FORTH HEREIN Printed in the U S A Rev 04 12 2012 ROSS CONTROLS All Rights Reserved Form SM058 ROSS CONTROLS ROSS CONTROLS ROSS CONTROLS ROSS CONTROLS
3. it indicates that the monitor has detected incorrect movement of the main valve elements and that there is a condition in the system that needs correcting Troubleshooting involves finding and correcting the condition that caused the lockout 4 2012 ROSS CONTROLS All Rights Reserved TROUBLESHOOTING Troubleshooting should be done only by persons trained and experienced in the servicing of pneumatic equipment If the trouble shooting is done at the installation instead of the repair bench take normal press operation safety precautions to avoid possible injury or damage to equipment The Troubleshooting Chart below can serve as a guide to locating and correcting malfunctions After the valve has been repaired it should be tested for normal operation by following the test procedures on page 4 If valve operation is still abnormal repeat the troubleshooting procedure If the valve fails to operate properly follow the Tests given in the chart below The TROUBLESHOOTING CHART Repair Procedures specified in the chart are detailed on the following pages Before returning the valve to normal service follow the Test Procedure given on page 4 Tests Symptoms Possible Causes Repair Procedure TEST 1 No lockout bleed and Inadequate air supply A Electrical power to solenoids no exhaust air Incorrect voltage at solenoids B must be off Remove silencer Both solenoids inoperative Cc Check for lockout bleed air
4. the inlet port 1 and is carried via passage 4 to spool C of the L G monitor It then goes around spool C and up passage 9 to the two 3 2 normally closed pilot valves F Spool C is the sensing element of the L G monitor and is kept in its center position by springs M Monitoring pressures are conveyed from points just above the inlet poppets U and V by the two passages 6 At the start of a normal operating cycle these pressures are equal SOLENOIDS ENERGIZED Simultaneously energizing the two solenoids a and b Figure 2 causes the two pilot poppets E to shift This closes the pilot exhaust passages and opens the pilot supply passages Pilot air can then go from passage 9 to the main valve pistons J via passages 5 Pressure on the pistons shifts the main valve elements This closes off the exhaust port 3 and connects the inlet port 1 to the outlet port 2 via the cross flow passages 10 and 11 With the main valve inlet poppets U and V open the monitoring passages 6 are open to inlet pressure This pressure is directed to both ends of spool C Because these monitoring signal pressures are equal spool C remains in its center position SOLENOIDS DE ENERGIZED Simultaneously de energizing solenoids a and b allows the two pilot poppets E to return to their normally closed positions Pilot pressure on the main valve pistons J is exhausted through exhaust port 3 via internal exhaust passages not shown The main valve elemen
5. L and M LEAKING PISTON SEAL A worn or damaged piston seal BB Figure 10 can allow pilot pressure to leak by the piston and cause erratic valve action and intermittent lockouts Disassemble to inspect seals See Repair Procedure K for disassembly instructions When installed a piston seal should have some compression in the bore It is advisable at this time also to inspect for varnish deposits and wear or damage to poppets and their seats Replace any worn or damaged parts If any parts show signs of deterioration incompatible lubricants or solvents may be the cause See paragraphs on compatible lubricants and cleaning on page 4 VARNISH DEPOSITS Varnish deposits in the valve may affect the movement of a piston and cause intermittent lockouts Varnish results from the action of oxygen on lubricating oils and can be aggravated by excess heat Varnish can also come from overheated compressor oil carried over into the airlines and deposited in the valve To disassemble for cleaning follow the procedure given in Repair Procedure K Use a water soluble detergent for cleaning varnished areas Avoid chlorinated solvents trichloroethylene for example and abrasive materials The former can damage seals and poppets and abrasives can do permanent damage to metal parts EXCESSIVE LUBRICATION Excess oil on the piston walls can sometimes cause erratic valve action and result in intermittent lock outs Although lubrication is not required by
6. ROSS double valves if an air line lubricator is used it should deposit only a thin film of oil on the piston walls Check lubricator for correct rate of oil flow A lubricator flow rate of one drop per minute when air is flowing is adequate for most applications UNDERSIZED OR PLUGGED SILENCER The silencer supplied with SERPAR Crossflow double valves is designed to create minimal back pressure However after long usage with contaminant laden air it may become clogged The increased back pressure can cause erratic movement of the valve elements and lead to intermittent lockouts A dirty silencer should be removed and cleaned with a water soluble detergent solution If a silencer other than the ROSS SERPAR silencer is used be sure that it is of the correct capacity Otherwise excessive back pressure may be immediately present and cause sluggish operation of the valve If a valve locks out intermittently but performs normally when the silencer is removed clean the silencer or replace it with one of the correct capacity CAUTION Restricting the exhaust port of a double valve can adversely affect its operation Silencers must be resistant to clogging and have a flow capacity greater than the exhaust capacity of the valve Figure 11 SERPAR Silencer ROSS expressly disclaims all warranties and responsibility for any unsatisfactory performance or injuries caused by the use of the wrong type wrong size or inadequately main
7. User Manual Ei gt 2 eS IODULNOI SSOH SERPAR DOUBLE VALVES i with L G MONITOR Sizes 8 1P 30 eS IODULNOI SSOH TABLE OF CONTENTS Page NORMAL VALVE OPERATION cccsseeseeesseeeeseeeeeeeeseeeseneeseeenseeseeeenaes 2 VALVE CONDITIONS RESULTING FROM A MALFUNCTION 3 INSTALLATION NOTES ns nssnensnnsnnnennnnannnnnnnnnannnnnnnnnnnnnannnannnnnnnnnannannnannnn 3 TEST PROCEDURE scsseccesecscccte cies sicedeadeulenestevsccevscceeectsucscsnasvccuexsaesenecss 4 MAINTENANCE sictcisi deste Hevceresiecitesttitieviahaen eal 4 TROUBLESHOOTING vvcsccccs cc cceecedesceavs sede cctcescusdecesccessstevvacececntastieeees sce 4 5 REPAIR PROCEDURES ws iscsccwcsscscccnssstevesscestecesierccncstsitenseveneeteniseaersteret 6 7 WARRANTY ee ceceeeessteeesseeeeenseeeeaseneeaseeeeeaseeesasseeeesseeeaseeeeeseneeenenneeaneeees 8 The two main valve elements in the SERPAR double valve move simultaneously during normal d operation If the valve elements fail to move simultaneously the L G monitor is designed to detect this condition The monitor reacts by exhausting pilot air and blocking pilot supply air so that further valve operation is inhibited The valve is then said to be locked out and cannot return to normal operation until the monitor is reset A lockout is not necessarily an indication that the valve has become faulty Rather it is an indication that the monitor has detected non simultaneous movement of the main valve
8. ake normal press operation safety precautions during this procedure in order to avoid injury or damage to equipment If cycling the valve does not clear the valve it will be necessary to disassemble the valve and clean it To disassemble the valve first turn off the electrical power to the valve then shut off the air supply and exhaust the air in the system Remove the pilot assembly L G monitor adaptor plate if used and junction box Read the note below before undertaking this disassembly Disassembly Note Before removing the pilot assembly the solenoid leads must be slipped off the solenoid terminals When the junction box is removed exercise care in withdrawing the solenoid leads from the passage through the valve body and monitor To remove the valve elements first remove the retaining rings H Figure 10 end plugs W and springs BA at the lower end of the bores Pull inlet poppets U and V off the valve stems and remove the remaining parts of the valve elements through the top of the valve body If the inlet poppets U and V are damaged or have deteriorated replace them Deteriorated poppet material suggests the use of incompatible lubricants Only lubricants such as those described on page 4 should be used While the valve is disassembled also inspect the piston poppets J for damage or deterioration Inspect the bores for varnish deposits or excess wear See Repair Procedures
9. ammed solenoid plunger Great overheating or delamination of the plunger can cause it to jam Such a solenoid must be replaced Defective solenoid coil Check resistance of each coil with an ohmmeter The coil is defective if resistance is zero or infinite The most common cause of solenoid burnout is incorrect supply voltage See Repair Procedure B If the coils are not defective examine the solenoids for the conditions described below Broken shading coil See S Figure 7 Copper shading coils reduce the solenoid s tendency to buzz when operated on alternating current If a shading coil is loose or broken the solenoid must be replaced Wear that causes a loss of air gap There must be a small gap between the solenoid plunger and the field frame when the solenoid is energized See air gap 17 Figure 7 If significant wear is apparent in areas 18 the air gap can be lost and the solenoid will buzz loudly when energized With this much wear the solenoid should be replaced s 18 Lubrication will help to prolong solenoid life by preventing some of the above troubles Solenoids should be lubricated periodically with a lithium based grease Put grease on the plunger and all impact surfaces Figure 7 Solenoid FAULTY PILOT INSERT Shut off electrical power to solenoids Shut off and exhaust the air supply Disassemble pilot section in the following way Remove pilot cover Q Figure 8 Slip leads off solenoid tab terminals and lift out sol
10. at Faulty seals on monitor spool E vent 12 and for exhaust air Contaminants in monitor G Have both lockout bleed Faulty seals on monitor spool E air and exhaust air Main inlet poppets not sealing J Pilot poppet not sealing D Jammed solenoid plunger Cc Have lockout bleed air Proceed to TEST 2 but no exhaust air TEST 2 Will not reset Faulty seals on monitor spool E With electrical power still off and silencer Bent lockout pin H removed attempt to reset monitor by Contaminants in monitor G applying pressure of not less than Resets correctly Proceed to TEST 3 to reset port 14 See Figure 6 TEST 3 Locks out intermittently Inadequate air supply A Take normal press operation safety Incorrect voltage at solenoids B precautions during this test to ensure Worn bore in monitor F that there is no danger to personnel Varnish deposits in valve L or equipment when the press cycles Excessive lubrication M With silencer removed and Monitor reset Valve performs normally Transient foreign material l cycle valve several times by energizing Dirty or undersized silencer N the solenoids in a normal manner Locks out on first cycle Proceed to TEST 4 TEST 4 Locks out as overrides Inadequate air supply A With electrical power off silencer removed are depressed Jammed solenoid plunger c and monitor reset proceed as follows Pilot poppet not sealing D Take normal press operat
11. d exhaust the air supply Proceed as follows 1 Remove pilot cover disconnect solenoid leads and remove pilot assembly 2 Remove pin X Figure 9 retaining ring Y and lockout pin assembly Z 3 Remove pin T retaining ring R end plug G and spring M 4 Remove spool C with your finger If the spool is stuck it will be necessary to remove the monitor from the valve body then apply low air pressure to sensing port 7 on the bottom face of the monitor As pressure is applied place your hand over the bore opening so that the spool does not fall out and become damaged Inspect the Teflon surfaces of the slipper seals for scratches or other defects that could affect their sealing 7 qualities If the seals are defective O O replace the entire spool and seal assembly Before reassembly inspect the bore for burrs or grit that might have O 2 damaged the seals See O O Repair Procedure F for Figure 9 Cross Section and remarks about bore wear Bottom Face of Monitor 6 2012 ROSS CONTROLS All Rights Reserved REPAIR PROCEDURES WORN SPOOL BORE A worn spool bore can cause the L G monitor to lockout because of poor sealing and consequent air leakage To check bore disassemble as described in Repair Procedure E If bore is worn or badly scratched the entire monitor must be replaced CONTAMINANTS IN SPOOL BORE A buildup of grease oil
12. des is not simultaneous the valve will lock out Release override N on the outlet side of the valve Outlet pressure should drop to approximately two percent of inlet pressure and there should be a flow of exhaust air On the back of the L G monitor are two bleed vents Figure 6 Bleed vent 12 should emit a continuous flow of air Release manual override P 4 Step 3 should have caused the L G monitor to lock out Depress both overrides simultaneously There should be no pressure at either the outlet or the exhaust port Bleed vent 12 should continue to emit air Release overrides 5 Reset the monitor by applying air pressure of at least 60 psig 4 bar to the pneumatic reset port 14 Air flow from bleed vent 12 should stop With reset pressure still applied energize both solenoids No action should occur Remove reset pressure 6 Depress both manual overrides simultaneously Release override P Conditions should correspond to those described in step 3 Release override N 7 Step 6 should have caused the L G monitor to lock out Depress both overrides simultaneously Conditions should correspond to those described in step 4 Release overrides 8 Reset the monitor as described in step 5 Bleed air should stop Install silencer The valve is now ready for normal operation MAINTENANCE Pneumatic equipment should be maintained only by persons trained and experienced in the maintenance of such equipment Supply Clean Air Forei
13. elements and that there is a condition in the system that needs correction The SERPAR double valve with L G monitor consists of four interconnected assemblies as shown in the illustration below The SERPAR double valve with L G monitor consists of four interconnected assemblies as shown in the illustration below Pilot Assembly Consists of two 3 2 normally closed solenoid controlled pilot valves in a single housing Each pilot valve controls one of the valve elements in the valve body assembly L G Monitor Assembly Contains a pressure controlled spool and mechanical lockout mechanism P O 5 S Valve Body Assembly The valve body has parallel flow paths including two s in to out crossflow paths The two main valve elements are 3 2 normally closed ma Junction Box Assembly Contains an electrical terminals trip in a housing with two threaded electrical conduit ports i L E E E E E E E E E E E E O E E E E E E E E E E E E E E E E a E E E E E E E Consider t DONE poppet valve elements plus spool elements that control air flow through the ROSS CONTROLS ROSS CONTROLS ROSS CONTROLS ROSS CONTROLS crossflow passages A silencer is bolted directly to the exhaust port eS IODULNOI SSOH NORMAL VALVE OPERATION CONDITIONS AT START Inlet air is blocked from the outlet by the two normally closed valve elements A and B Figure 1 The outlet port 2 is connected to the exhaust port 3 Pilot supply air comes from
14. enoids To check solenoids see Repair Procedure C Remove rubber cushions CA from tops of inserts With Truarc type pliers remove retaining rings CB 5 Remove inserts by grasping them at the shoulder area and pulling with a circular motion Removing inserts by pulling on the spring or stem may damage the inserts 6 Be sure that poppet return springs CC are removed 7 Check action of each insert The stem should move easily with light finger pressure and should not jerk or grab during its travel about 03 inch If a stem does not move smoothly the insert should be replaced Inspect the poppets E and their seats for foreign particles or damage If the poppets are swollen or have deteriorated improper lubricants may be the cause See page 4 for information about compatible lubricants If a poppet or inlet upper seat is defective the insert must be replaced Blow out passages 5 and 9 to remove loose dirt particles If an exhaust lower seat is defective the entire pilot must be replaced po eo Figure 8 Cross Section of Pilot Assembly FAULTY SEALS ON MONITOR SPOOL Faulty seals on spool C Figure 9 can result in air leaks or cause the spool to jam so that the L G monitor does not function properly Before beginning disassembly to inspect the L G monitor shut off electrical power to the solenoids Shut off an
15. ent of inlet pressure Therefore use only a properly sized and designed silencer See CAUTION on page 7 ROSS Pneumatic Reset Port 14 Use an air supply of not less than 60 psig 4 bar and a 3 2 manually or solenoid controlled reset valve Electrical Conduit Port 15 Itis very important that the electrical supply be of the correct voltage and frequency ROSS solenoids are rated for continuous duty at 85 to 110 of the voltage shown on the pilot housing A supply voltage that does not fall within this range can cause nuisance lockouts or premature solenoid burnout If electrical power is supplied by a transformer it must be capable of handling the inrush current of the solenoids without significant voltage drop Mounting Position It is recommended that ROSS double valves be mounted with the pilot assembly upward Pressure Range ROSS double valves have an operating pressure range of 30 to 125 psig 2 to 8 5 bar Pressure below this range can create the potential for injury by reducing the speed with which the outlet volume is pressurized or by rendering the monitor inoperative It can also cause intermittent lockouts Pressure above the specified range causes excessive poppet impact and can shorten the life of the valve Temperature Range ROSS double valves have an operating media temperature range of 40 F to 175 F 4 C to 80 C and an ambient temperature range of 40 F to 120 F 4 C to 50 C Improper valve action and or a s
16. essure at port 16 is equal to line pressure but during a lockout pressure drops to zero This drop is due to the pilot air passage 9 being vented to atmosphere as described above If port 16 is not used it must be plugged Figure 4 Cross Section of L G Monitor RESETTING THE L G MONITOR Caution To avoid the potential for injury and to ensure that the equipment controlled by the valve does not begin operating immediately after resetting the monitor electrical power to the solenoids must be off Otherwise the energized solenoids will actuate the valve as soon as the reset pressure signal is removed After the cause of a lockout has been corrected the spool in the monitor must be reset in its normal center position in order for the valve to function This is done by applying an air pressure signal of at least 60 psig 4 bar to the pneumatic 4 E T reset port 14 Figure 4 Pressurizing port 14 produces two results 1 lockout Spoo 4 7 K win K ae pin K is lifted out of the lockout groove so that the centering springs M can return to Left Ai Ai to Right the spool to the center position and 2 differential spool L is shifted so that it blocks pilot air passage 9 thereby cutting off pilot air supply during the resetting process This keeps the valve inoperative while resetting air pressure is applied so that any attempt to circumvent the functions of the L G monitor is inhibited Figure 5 Lockout Posi
17. for very long under size or pinched supply lines sharp bends and restrictive fittings All can reduce the air volume supplied to the valve B INCORRECT VOLTAGE AT SOLENOIDS ROSS solenoids are rated for continuous duty at 85 to 110 of the voltage shown on the pilot housing A supply voltage that does not fall within this range can cause nuisance lockouts premature solenoid burnout or impact damage To check the electrical supply remove the junction box cover at the bottom of the valve and attach voltmeter leads to the supply terminals Read the voltmeter while the solenoids are energized If the voltage falls below the allowable operating range the electrical supply is inadequate even though the supply voltage might be correct without the electrical load A voltage that exceeds the allowable maximum can cause premature solenoid burnout loss of air gap due to impact damage or a stuck solenoid plunger See Repair Procedure C below FAULTY SOLENOID OPERATION Before removing solenoids for inspection check to see if the pilot cover is loose A loose cover can prevent full travel of one or both pilot valves However the valve can operate normally if manual actuation is used because the manual pressure pushes the solenoids down into their correct positions If the cover is not loose shut off electrical power to the solenoids remove pilot cover slip wires off solenoid terminals and remove both solenoids Check for the following J
18. gn material lodging in valves is a major cause of breakdowns The use of a 5 micron rated air filter located close to the valve is strongly recommended The filter bowl should be drained regularly and if its location makes draining difficult the filter should be equipped with an automatic drain Check Lubricator Supply Rate A lubricator should put a fine oil mist into the air line in direct proportion to the rate of air flow Excessive lubrication can cause puddling in the valve and lead to malfunctions For most applications an oil flow rate in the lubricator of one drop per minute is adequate Note that the double valve does not itself require airline lubrication See below for information about lubricants that are compatible with the materials used in the double valve and are suitable for use in compressed air systems Compatible Lubricants Although this valve does not require air line lubrication it may be used with lubricated air being supplied to other mechanisms Some oils contain additives that can harm seals or other valve components and so cause the valve to malfunction The best oils to use are those specifically compounded for air line service These are generally petroleum base oils with oxidation inhibitors an aniline point between 180 F 82 C and 220 F 104 C and an ISO 32 or lighter viscosity Cleaning the Valve If the air supplied to the valve has not been well filtered the interior of the valve may accumulate dir
19. hortening of valve life can result if these temperature limits are not observed www rosscontrols com 3 TEST PROCEDURE ROSS valves are thoroughly tested after assembly for proper operation It is recommended that the following tests be made when the valve is initially installed or whenever the valve has been disassembled These tests should be made at the repair bench and at the installation At the installation take normal press operation safety precautions during these tests to avoid possible injury or damage to equipment All tests should be performed only by persons trained and experienced in the testing of pneumatic equipment These tests call for the use of the manual overrides If your valve is not so equipped use the corresponding solenoids instead This will require wiring the solenoids so that they can be individually energized If the valve fails any of these tests refer to Troubleshooting beginning on page 4 1 Remove silencer Apply compressed air in the 30 to 125 psig 2 to 8 5 bar range to inlet port 1 see Figure 6 There should be no pressure at outlet port 2 or exhaust 3 2 Connect outlet port 2 to a small volume 25 50 cubic inches fitted with a damped pressure gauge Simultaneously energize both solenoids Inlet and outlet pressures should be equal There should be no leakage at the exhaust port De energize both solenoids 3 Depress both manual overrides simultaneously If the actuation of the overri
20. ion safety precautions Varnish deposits in valve L to ensure that there is no danger to personnel Excessive lubrication M or equipment when the press cycles Leaking piston poppet seal K Actuate the valve by depressing holding Locks out as overrides Varnish deposits in valve L then releasing both manual overrides are released Excessive lubrication M Be sure to depress overrides simultaneously Operation normal Faulty solenoid c with overrides N P Manual overrides ee z Saat Pat External Ports and Overrides 3 Exhaust Silencer 12 13 Monitor Bleed Vents 14 Pneumatic Reset Port 14 16 1312 15 Electrical Conduit Port 16 Lockout Indicator Port www rosscontrols com 5 REPAIR PROCEDURES INADEQUATE AIR SUPPLY Even though the air supply pressure is in the correct 30 to 125 psig 2 to 8 5 bar range the air volume supplied can be too small An inadequate air supply volume causes excessive pressure drop during valve actuation i e pilot air supply is sufficient to unseat the main valve elements but the pressure drop which results from filling the outlet volume depletes the pilot air supply The main valve elements may be only partially actuated so that inlet air flows out the exhaust The lowered pilot pressure can also exaggerate the effects of small differences in the operating characteristics of pilots and valve elements so that the valve elements may not move simultaneously This can produce intermittent valve lockouts Check
21. or water in the spool bore can restrict or prevent movement of the spool This can create an unsafe condition by preventing the L G monitor from locking out when it should or can prevent resetting after a lockout has occurred To inspect and clean the bore follow disassembly steps in Repair Procedure E BENT LOCKOUT PIN If lockout pin K Figure 9 is bent it will not retract when resetting pressure is applied and the monitor remains locked out To remove the lockout pin follow steps 1 and 2 in Repair Procedure E Assembly with a new pin is the reverse of disassembly TRANSIENT FOREIGN MATERIAL If the valve resumes normal operation after being reset the cause of the lockout may have been a transient foreign particle A bit of scale or other foreign material could lodge at various points in the valve to cause a nuisance lockout After resetting the air flow of the next operating cycle can wash the foreign material out thus permitting the valve to return to normal operation This situation is most common after a period of press inactivity An efficient filter located close to the valve will help to eliminate this problem J MAIN INLET POPPET NOT SEALING If one of the inlet poppets is not sealing air can be detected escaping at the exhaust port Foreign particles are sometimes responsible for holding a poppet off its seat Manually cycle the valve several times to see if the flow of air through the valve will flush out the particles T
22. t and varnish which can affect the valve s performance Although very tolerant COMPATIBLE LUBRICANTS Brand Name American Industrial Oil 32 Amoco Spindle Oil C Amolite 32 Pacemaker 32 Spinesstic 22 Teresstic 32 Velocite 10 Air Lube 10H NR Turbo T32 Sunvis 11 Sunvis 722 Regal R amp O 32 Union Turbine Oil of dirty air the valve may sometimes need cleaning To clean the valve use any good commercial solvent or kerosene Do not use a chlorinated solvent or abrasive materials The former damages seals and abrasives can do permanent damage to metal parts Before reassembling the valve lubricate all sliding surfaces with a grease such as Dow Corning BR 2 Electrical Contacts In the electrical circuits associated with the valve solenoids keep all switches or relay contacts in good condition to avoid solenoid malfunctions Replace Worn Components In most cases it is not necessary to remove the valve from its installation for servicing However turn off the electrical power to the valve shutoff the air supply and exhaust the air in the system before beginning any disassembly operation TROUBLESHOOTING The SERPAR double valve with L G monitor is designed to monitor the outlet pressures of the main valve elements If the valve elements fail to move synchronously the monitor is designed to detect this condition and to lock out the valve A lockout is not necessarily an indication that the valve is faulty Rather
23. tained silencer installed with a ROSS product www rosscontrols com 7 ROSS GLOBAL Reach with a LOCAL Touchs ROSS CONTROLS ROSS EUROPA GmbH Troy MI U S A Langen Germany Telephone 1 248 764 1800 Telephone 49 6103 7597 0 Fax 1 248 764 1850 Fax 49 6103 74694 In the United States Email info rosseuropa com Safety Department 1 248 764 1816 www rosseuropa com Customer Service 1 800 GET ROSS 438 7677 Technical Service 1 888 TEK ROSS ROSS ASIA K K 835 7677 Kanagawa Japan www rossconirois com Telephone 81 427 78 7251 Fax 81 427 78 7256 ROSS UK Ltd www rossasia co jp Birmingham United Kingdom Telephone 44 121 559 4900 Fax 44 121 559 5309 ROSS CONTROLS CHINA Ltd Email sales rossuk co uk Shanghai China Telephone 86 21 6915 7951 Fax 86 21 6915 7960 www rosscontrolschina com ROSS SOUTH AMERICA Ltda Sao Paulo Brazil CEP 09725 020 Telephone 55 11 4335 2200 Fax 55 11 4335 3888 Email vendas ross sulamerica com br ise rte ela INDIA Pvt Ltd Telephone 91 44 2624 9040 Fax 91 44 2625 8730 Email rossindia airtelmail in Your local ROSS distributor is DIMAFLUID s a s Saint Ouen France Telephone 33 01 4945 6565 Fax 33 01 4945 6530 Email dimafluid dimafluid com www dimafluid com Warranty All products sold by ROSS CONTROLS are warranted for a one year period with the exception of all Filters Regulators and Lubricators FRLs
24. tions of L G Spool INSTALLATION NOTES Pneumatic equipment should be installed only by persons trained and experienced in the installation of pneumatic equipment Air Lines Before installing a ROSS double valve in an existing system the air lines must be blown clean of all contaminants Experience has shown that one of the leading causes of lockouts is foreign material from the air lines which becomes lodged in the valve It is strongly recommended that an air filter be installed ahead of and close to the valve ROSS recommends a 5 micron rated filter Valve Inlet 1 See Figure 6 DO NOT RESTRICT THE AIR SUPPLY Any restriction of the air supply lines for example sharp bends or undersized lines will reduce the speed with which the outlet volume is pressurized See Inadequate Air Supply page 6 for further discussion Valve Outlet 2 For faster pressurizing and exhausting of the outlet volume put the valve as close as possible to the mechanism being operated Also any restriction in the outlet lines will reduce pressurizing and exhausting speeds Valve Exhaust 3 DO NOT RESTRICT THE EXHAUST Limiting the exhausting speed decreases an important safety feature of the double valve During a malfunction in which only one of the valve elements has shifted air escaping past the spool in the valve stem of the closed valve element see Figure 3 must be quickly exhausted to keep outlet pressure at or below the design pressure of two per c
25. ts A and B return to their normal deactuated positions Inlet air is again blocked from outlet port 2 by poppets U and V Pressure at outlet port 2 at the ends of spool C and in the monitoring passages 6 is exhausted through exhaust port 3 This completes the normal operating cycle and the valve has returned to the Conditions at Start described above VALVE CONDITIONS RESULTING FROM A MALFUNCTION DURING A MALFUNCTION Due to a mechanical or electrical malfunction one of the valve elements may not respond to its energizing signal or alternatively may not return to its normal position after the signal is removed In either case we have the condition depicted in Figure 3 one valve element closed one open Inlet air flowing past open poppet U and into crossflow passage 10 is practically blocked by spool SB on valve element B Although some air can pass around spool SB the amount is so small and the exhausting capacity of the valve so large that the pressure at outlet 2 does not exceed two per cent of inlet pressure Figure 1 Solenoids Not Energized p 1 10 11 i i Figure 2 Solenoids Energized
Download Pdf Manuals
Related Search