WO1999009341A1 - Soupape pilotee de modulation sans ecoulement - Google Patents

Soupape pilotee de modulation sans ecoulement Download PDF

Info

Publication number
WO1999009341A1
WO1999009341A1 PCT/US1998/016080 US9816080W WO9909341A1 WO 1999009341 A1 WO1999009341 A1 WO 1999009341A1 US 9816080 W US9816080 W US 9816080W WO 9909341 A1 WO9909341 A1 WO 9909341A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
valve
pilot
chamber
system pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US1998/016080
Other languages
English (en)
Inventor
Craig F. Bliss
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CROSBY VALVE Inc
Original Assignee
CROSBY VALVE Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CROSBY VALVE Inc filed Critical CROSBY VALVE Inc
Priority to AU86060/98A priority Critical patent/AU8606098A/en
Publication of WO1999009341A1 publication Critical patent/WO1999009341A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
    • F16K17/02—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side
    • F16K17/04—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded
    • F16K17/10—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded with auxiliary valve for fluid operation of the main valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
    • F16K17/02—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side
    • F16K17/04—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded
    • F16K17/10—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded with auxiliary valve for fluid operation of the main valve
    • F16K17/105—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded with auxiliary valve for fluid operation of the main valve using choking or throttling means to control the fluid operation of the main valve

Definitions

  • This invention relates generally to fluid pressure relief valves of the type operated by a pilot valve, and more particularly to such pilot valves which do not conduct system fluid when the main pressure relief valve is open and flowing.
  • Non-flowing pressure relief valves have demonstrated superior performance because they are not influenced by flowing fluid, which may cause icing or other conditions, unrelated to the system pressure, that could adversely affect their operation. Since the primary function of the pressure relief valve is to protect against system pressure exceeding a maximum or set pressure, this attribute of non-flowing pilot valves is highly desirable.
  • the present invention provides such a non-flowing pilot valve which reduces the loss of system fluid and pressure though the main pressure relief valve by assuring that the main valve is fully closed just below the predetermined set pressure, which assures that system pressure is supplied to the dome chamber of the main pressure relief valve until the system pressure reaches just a small percentage below the predetermined set pressure,, which assures the main pressure relief valve is fully open before the system pressure reaches 110 percent of the predetermined set pressure, which causes the disc of the main pressure relief valve to operate in modulating fashion from being slightly open at system pressures just above set pressure to being fully open at 110 percent of set pressure, which also causes the disc of the main pressure relief valve to operate in modulating fashion as the system pressure decreases from 110 percent to set pressure, and which has internal components that require less critical manufacturing tolerances and hence is relatively simple to manufacture, assemble and maintain.
  • Figure 1 is a schematic representation of a pilot valve according to the present invention connected to a conventional main pressure relief valve shown in vertical section;
  • Figure 2 is a view in vertical section of the pilot valve shown in Fig. 1 ;
  • Figure 3 is a view in vertical section of the lower portion of the pilot valve shown in Fig. 2;
  • Figure 4 is an enlarged view of a portion of the pilot valve shown in Fig. 3 with clearances exaggerated for clarity.
  • a conventional pilot-operated, main pressure relief valve having main valve body 12 with an inlet 14 connected in fluid communication with the pressurized fluid system to be controlled by the main valve 10 and an outlet 15 connected to exhaust.
  • a main valve disc 16 is reciprocably mounted in the body 12 and is engageable with a main valve seat 18 to seal or block communication between the inlet 14 and the outlet 15.
  • a top plate 20 is sealingly attached to the body 12 and forms, with the main valve disc 16, a main valve dome chamber 22. Pressure in the dome chamber 22 acts to urge the main valve disc 16 against the seat 18, as does a compression return spring 24 interposed between the top plate 20 and the main valve disc 16.
  • the pressure in the main valve dome chamber 22, which is controlled by the pilot valve 26, must be lower than the system pressure for the main valve disc 16 to open.
  • the pressure differential between the main valve dome pressure and system pressure necessary to unseat or open the main valve disc 16 is commonly referred to as the upset ratio.
  • the pilot valve 26 has a pilot inlet conduit 28, which as shown is directly connected to the inlet 14 of the main valve 10 but may be connected at a location remote therefrom, to communicate system pressure to the pilot valve 26.
  • a second pilot dome conduit 30 connects the main valve dome chamber 22 of the main valve 10 with the pilot valve 26, and a third pilot exhaust conduit 32 connects the pilot valve 26 to exhaust, which for convenience may be the outlet 15 of the main valve 10 downstream of the main valve seat 18, as shown, but may be any suitable connection to low pressure, such as atmospheric. As best seen in Figs.
  • the pilot valve 26 has a pilot valve body 34 with a recess having a guidance bore engageable with a complementary section on a replaceable piston adapter 36 which has a through bore in which a sense piston 38 is reciprocably mounted.
  • the piston adapter 36 may be replaced to accommodate sense pistons 38 with different diameters than the one shown in order to vary the effective area and hence the force exerted by any given pressure acting on the lower side thereof.
  • the 0-ring seals on the sense piston 38 may be eliminated and a diaphragm 56 of suitably flexible material clamped between the piston adapter 36 and the pilot valve body 34 in order to obtain larger force for a given pressure acting on the lower side of the sense piston 38 (see Fig.
  • a pilot valve bonnet 40 is secured to the pilot valve body 34 by bolts 42 and nuts 43 engaging the threaded ends thereof.
  • a compression range spring 44 is trapped between an upper spring washer 46 and a lower spring washer 48, which has a recess for accepting a complementary projection formed on the upper end of the sense piston 38 to transfer the force exerted by the compressed range spring 44 to the sense piston 38.
  • the upper spring washer 46 engages a threaded pilot adjusting sleeve 50 extending through a threaded opening in the top of the pilot valve bonnet 40.
  • the sleeve 50 permits fine adjustment of the pre-compression imposed on the range spring 44, and hence the minimum spring force applied to the sense piston 38, with a lock nut 52 engaging the threaded adjusting sleeve 50 to permit securing the desired adjustment.
  • a removable protective pilot cap 54 is preferably provided to cover the adjusting sleeve 50 and lock nut 52, with the pilot valve bonnet 40 having an opening 47 connecting its interior to atmosphere.
  • the pilot valve body 34 is provided with a bore 60 and counter bores forming a longitudinal channel with an enlarged chamber 62 at its upper end which is always in communication with system pressure through pilot inlet conduit 28.
  • the pressure in system chamber 62 acts on the effective area of the sense piston 38 creating a force to urge the piston 38 upward in opposition to the force of the range spring 44.
  • a sleeve assembly 64 is slidable in the bore 60 and formed, for ease of manufacture and assembly, of two parts 65 and 66 firmly abutting and affixed to one another by a threaded connector 68 engaging the lower end of the upper part 65 and the upper end of the lower part 66.
  • the upper part 65 is connected to, .and hence moveable with, the sense piston 38 by threaded engagement of a central projection 70 on the upper part 65 with a blind hole extending upward from the lower end of the sense piston 38.
  • the upper part 65 has a longitudinal blind bore 72 and cross drilled passages 74 to communicate system pressure from the pilot inlet conduit 28 to the bore 72.
  • the lower part 66 has a longitudinal through bore 76 of smaller diameter than the blind bore 72 with a stem assembly 78 reciprocably mounted therein.
  • the outer diameter of the lower part 66 reciprocates in a dome spool 77 inserted from the lower end of and secured to the pilot valve body 34 with a dynamic seal 79 carried by the lower part 66 sealingly engaging the spool 77.
  • the stem assembly is formed of an upper member 78 reciprocably mounted in, and having a diameter smaller than, the through bore 76 so that fluid may flow therebetween.
  • the upper end of the member 78 is formed with an enlarged cylindrical head 80 which is reciprocable in, and of a smaller diameter than the blind bore 72 so that fluid may flow therebetween.
  • a compression stem assembly spring 82 is trapped between the end of the blind bore 72 and the top of the stem assembly head 80.
  • the upper end of the bore 76 in the lower part 66 is machined at an angle to form a valve seat and the lower end of the head 80 is machined at a different angle to form an inlet valve, the different angles creating line contact and thus a good seal therebetween.
  • the stem assembly spring 82 tends to urge the head 80 on the upper member 78 of the stem assembly into contact with the upper end of the lower part 66 of the sleeve assembly to block fluid communication between blind bore 72 and the bore 76.
  • the stem assembly also includes an exhaust valve seat retainer 84 and an exhaust seat shoulder 86 which are threaded onto the upper member 78 so that the seat retainer 84 abuts a shoulder formed on the upper member 78 and the seat shoulder 86 abuts the seat retainer to form, with the upper member 78, a unitary structure.
  • An O-ring 88 is trapped between the seat retainer 84 and the seat shoulder 86 when the shoulder 86 is threaded into abutment with the retainer 84.
  • the O-ring 88 is initially seated in an annular groove formed in the retainer 84, which groove has a radius slightly less than the radius of the cross section of the relaxed O-ring 88 and an overall diameter slightly greater than the overall diameter of the relaxed O-ring 88 and is engaged by a similar groove formed in the shoulder 86 so that when the shoulder 86 abuts the retainer 84 the O-ring 88 is subjected to axial compression, circumferential tension and horizontal compression, which causes the O-ring 88 to become stiffer.
  • An exhaust seat 90 threads into the pilot valve body 34 to trap the dome spool 77 against a shoulder in the body 34 and has a longitudinal bore 91 , the upper circular edge of which is engageable by the O- ring 88, in which the lower end of the seat shoulder 86 reciprocates.
  • the pilot dome conduit 30 communicates through the dome spool 77 with the annular space between the retainer 84, and the pilot exhaust conduit 32 communicates with the annular space between the exhaust seat shoulder 86 and the exhaust seat 90.
  • the O-ring 88 functions as an exhaust valve to isolate the pilot dome conduit 30 from the pilot exhaust conduit 32 when closed, i.e. when in engagement with the exhaust seat 90, and to connect the pilot dome conduit 30 with the pilot exhaust conduit 32 when open, i.e.
  • the stiffness imparted to the O-ring 88 helps to reduce the deadband, i.e. the amount of travel required of the range spring 44 necessary for the O-ring 88 to disengage from the exhaust seat 90, and thereby open the exhaust valve.
  • the outer end of the bore 91 is sealed by a plug 96.
  • the volume within the bore 91 between the lower end of the seat shoulder 86 and the upper end of the plug 96 defines a dome balance chamber 98 which communicates with the pilot dome conduit 30 through an internal passage 100 formed in the stem assembly 78.
  • Pressure in the dome balance chamber 98 which is always in communication with the main valve dome chamber 22, is controlled by the actions of the inlet valve and the outlet valve.
  • the sleeve assembly 64 there are only two moving parts within the pilot valve 26, viz. the sleeve assembly 64 and the stem assembly.
  • the sleeve assembly is free to reciprocate in the channel, but with its downward movement limited by engagement of a flange 67 on lower part 66 with the dome spool 77.
  • the dimensions of the parts are such that when system pressure is below the set pressure, the exhaust valve is seated, the flange 67 is in engagement with the dome spool 77, and the inlet valve is open, i.e. the head 80 is spaced above the upper end of the lower part 66 of the sleeve assembly.
  • the pressure at which this occurs is determined by the compressive force of the range spring 44 as set by adjustment of the adjusting sleeve 50.
  • main valve disc 16 When the pressure in main valve dome chamber 22 drops below the upset ratio, system pressure will raise the main valve disc 16 off its seat 18. Again, negative feedback, i.e. the loss of pressure on the lower side of the dynamic seal 79 will permit the range spring 44 to re-close the exhaust valve halting the loss of pressure from the main valve dome chamber 22. Thus, the main valve disc 16 will open only a proportional amount. Raising system pressure above the set value will again open the exhaust valve permitting a bleed off of main valve dome 22 pressure which is proportional to the increase in system pressure. As a result, the main valve disc 16 will also rise or open a proportional amount until the system pressure reaches a value between 5 percent and 8 percent above set pressure when the main valve disc 16 will be fully open.
  • the pilot valve 26 is capable of a modulating action, rather than a snap action, in reaction to both small increases and decreases in system pressure, but will provide snap action opening of the main valve disc 16 in response to large increases in system pressure. That is, if the system pressure rises only slightly above set pressure, the pilot valve 26 will bleed the pressure in the dome chambers to a value which is just below the upset ratio of the main valve 10, allowing the main valve disc 16 to open only slightly to relieve the overpressure condition at a slow flow rate and to re-close the main valve disc 16 when the overpressure condition has been relieved.
  • the pilot valve 26 will bleed the dome chambers to a lower pressure proportional to the overpressure causing the main valve disc 16 to open to a greater degree to flow fluid to the exhaust outlet 15 at a higher rate. Then as the pressure drops the pilot valve 26 will modulate the main valve disc 16 back down to closed position. If at any time, the system pressure rises sharply above set pressure, the sense piston 38 will move upward compressing the range spring 44 a greater distance corresponding to the sharply higher system pressure. The sleeve assembly 64 will be pulled upward an equal distance causing the inlet valve to close and the stem assembly, which is pulled upward by the sleeve assembly, to rapidly open the exhaust valve.
  • the dome chambers will be in full communication with the exhaust line 32 causing the main valve disc 16 to rapidly move to a full open position in a snap action manner.
  • the pilot valve and the main valve 10 will remain stable in this condition until the system pressure begins to drop. Since system pressure usually falls gradually, the pilot valve 26 will modulate the main valve disc 16 back down to a closed position as the system pressure decreases to set pressure, in the manner described above.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Safety Valves (AREA)
  • Control Of Fluid Pressure (AREA)

Abstract

L'invention concerne une soupape pilotée (26) destinée à commander une soupape de décharge (10) comprenant une chambre de pression (62) en communication permanente avec la pression du système formée à l'extrémité supérieure d'un canal et présentant un piston de détection (38) sur lequel agit la pression du système et un ressort de compression (44). Un ensemble manchon, coulissant dans le canal et relié au piston de détection, comprend un ensemble tige coulissant intérieurement pour former une chambre (73) à dôme piloté; les deux ensembles formant une soupape d'entrée destinée à orienter la pression du système vers la chambre à dôme piloté. Un ressort (82) de la soupape d'entrée agit sur celle-ci en la fermant et sur n'importe quel orifice de la soupape d'évacuation de la chambre à dôme pour l'évacuer ou bien isoler ladite chambre à dôme.
PCT/US1998/016080 1997-08-15 1998-07-31 Soupape pilotee de modulation sans ecoulement Ceased WO1999009341A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU86060/98A AU8606098A (en) 1997-08-15 1998-07-31 Non-flowing modulating pilot valve

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US91196597A 1997-08-15 1997-08-15
US08/911,965 1997-08-15

Publications (1)

Publication Number Publication Date
WO1999009341A1 true WO1999009341A1 (fr) 1999-02-25

Family

ID=25431182

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/016080 Ceased WO1999009341A1 (fr) 1997-08-15 1998-07-31 Soupape pilotee de modulation sans ecoulement

Country Status (3)

Country Link
AU (1) AU8606098A (fr)
WO (1) WO1999009341A1 (fr)
ZA (1) ZA987263B (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005050072A1 (fr) * 2003-11-19 2005-06-02 Marco Systemanalyse Und Entwicklung Gmbh Soupape de limitation de pression
WO2010124661A1 (fr) * 2009-05-01 2010-11-04 Yang Cong Dispositif de régulation de pression, système d'alimentation en air comprimé et véhicule à moteur
WO2021016471A1 (fr) * 2019-07-24 2021-01-28 Emerson Automation Solutions Final Control US LP Soupape pilote de chargement à dôme rapide

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2584523A (en) * 1949-03-28 1952-02-05 Beaton & Cadwell Mfg Co Inc Pressure relief valve
US4609008A (en) * 1985-09-11 1986-09-02 Anderson-Greenwood Usa, Inc. Non-flowing pressure responsive pilot valve
WO1987005134A1 (fr) * 1986-02-19 1987-08-27 Vapor Corporation Soupape pilote regulatrice de surpression
WO1998008015A1 (fr) * 1996-08-23 1998-02-26 Flow Safe, Inc. Soupape de surete et de decharge pilotee

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2584523A (en) * 1949-03-28 1952-02-05 Beaton & Cadwell Mfg Co Inc Pressure relief valve
US4609008A (en) * 1985-09-11 1986-09-02 Anderson-Greenwood Usa, Inc. Non-flowing pressure responsive pilot valve
WO1987005134A1 (fr) * 1986-02-19 1987-08-27 Vapor Corporation Soupape pilote regulatrice de surpression
WO1998008015A1 (fr) * 1996-08-23 1998-02-26 Flow Safe, Inc. Soupape de surete et de decharge pilotee

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005050072A1 (fr) * 2003-11-19 2005-06-02 Marco Systemanalyse Und Entwicklung Gmbh Soupape de limitation de pression
CN100366966C (zh) * 2003-11-19 2008-02-06 马可系统分析和发展有限公司 减压阀
WO2010124661A1 (fr) * 2009-05-01 2010-11-04 Yang Cong Dispositif de régulation de pression, système d'alimentation en air comprimé et véhicule à moteur
RU2526612C2 (ru) * 2009-05-01 2014-08-27 Янг Конг Устройство для регулирования давления, система подачи сжатого воздуха и автомобильное транспортное средство
WO2021016471A1 (fr) * 2019-07-24 2021-01-28 Emerson Automation Solutions Final Control US LP Soupape pilote de chargement à dôme rapide

Also Published As

Publication number Publication date
ZA987263B (en) 1999-02-15
AU8606098A (en) 1999-03-08

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