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1. GB532599 - Improvements in or relating to safety valves

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

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PATENT SPECIFICATION
Application Date: Sept i i, 1939 No 25524/39.
Complete Specification Left: Dec 27, 1939.
Complete Specification Accepted: Jan 28,; 941.
PROVISIONAL SPECIFICATION
532,399 Improvements in or relating to Safety Valves We, COCK Bn U Ns L Imi TED, a British Company, JAMES I{ODGBB and T HoÄm AS GRANT, both of British Nationiality, all of the Compaay's address at Clydesdale Engi-neerinu, Works, Cardonald, Renfrewshire, do hereby declare the nature of this invention to be as follows This invention relates, to improvements in pressure fluid safety valves.
A safety valve according to the invention includes a safety valve element which is adapted to perform so-called high-iift " travel against spring or other loading located externally of the safety valve chest and acting on the valve element througgh the medium of a preferably upright spindle on the lower end of which the valve element is centered The valve element co-operates with an orificed seat member secured within the valve chest; the central portion of the valve element preferably converging dow-nw ardly into the seat orifice and presenting a conical sucket for re(ep)tion of a conical nose on the lower end of the spindle The valve element is unitary with an upstanding cylindrical wvall forming therewith a pot structure loosely fitted with a lid member penetrated by the spindle and including a cylindrical skirt or boss which depends and is a sliding fit within the bore of the pot The lid member is preferably formed with a peripheral flange which overhangs a peripheral flange on the upper end of the pot, the flange of the lid member fbeing provided on its underside with an annular ridge which rests oil the ulp)per enda of the pot Pressure fluid is adapted to be admitted into tie int ior of the pot as hereinafter described, when tile valve element is unseated, wherebly to force the lid member upwardly aild to cause an annular sealing faf e on the upper surface thereof to enter into sealing engagement with an annular abutment sealing face on the lower or inner end of a valve snindle guide hush secured in the cover of the safety valve chest, said bush being formed with a snlined, fluted, or otherwise machiund bore devised to afford edge or point contact only for guidance therethroih of the spindle, so that the spindle may slide in the bush with minimum frictional 55 restraint.
Closely surrounding the pot is a laterally-ported loose cylindrical sleeve which rests at its lower end on the valve seat member The lower portion of the 60 sleeve surrounds the interengaging valve and seating faces and forms the outer boundary of an annular recess hereinafter referred to.
The diameter of the valve -face is 65 substautially less than the external diameter of the pot and there is formed in the valve element, around and above the valve face, an annular recess which is c ounded on its external circumference by 70 the lower portion of the sleeve and which first receives pressure fluid released by the valve element A small orifice (or orifices) provided in the valve element connects the aniular recess with the 75 interior of the pot The seat face is scurrounded by an annular cavity forming part of the said recess and bounded on its outer periphery by an annular rim upstandinlg fromn the seat member into 80 the recess The lower end portion of the sleeve is so constricted as closely to suirround the rim.
The ports in the sleeve are pitched around the circumference thereof and 85 a.re located above the level of a circumferential edge of the valve element which defines the upper limit of the aun-lar recess.
In operation, when the fluid pressure 90 On the upstream or under side of the valve element is such that the valve element is uiueatedl, the released pressure fluid enters the annular recess and exercises further thrust in valve-opening direction 95 on the supplementary area of the valve element exposed within the recess, so that the valve element shoots rapidly to " high lift i)osltii Olin which position the valve element 100 inmmasks the ports in the sleeve and thus affords free outlet for tble released pressure fluid In the initial opening movement of the valve element, pressure fluid also flows from the annular recess 105 throug-h the orifice into the pot and 532,599 forces the lid member upwardly until the sealing face on the upper surface of the lid member engages the abutment sealing face on the bush, and thus prevents escape of fluid through the space between the spindle and the bore of the bush into the space above the valve chest cover whichl houses the valve-loadinog spring or springs When the valve element cloes the lid member drops back into its normal position on top of the pot.
Should the sleeve stick to the circumference of the pot for any reason, the sleeve will rise with the valve element and the released pressure fluid will have 15 free egress through the annular gap formed between the seat menilber and the elevated lower end of the sleeve.
As will be understood, the construction is such that the valve element is ensured 2 o maximniun free(loni for movement, and high-lift ' operation is obtained without the use of an auxiliary piston.
Dated this 9th (lay of Septembler 19:39.
CXIIU SHIANI & i FAIRTEATHER, 86 St Tincent Street, Glasgow, C and 6.5 /66 Chancery lne, London, W C 2, Ageits for the Applicants.
COMPLETE SPECIFIAT 1 OIO Improvements in or relating to Safety Valves We, Cooioun Rxs L Im TED, a British Company Jtn MES RODGEL and T Ho MAS GRANT, both of British Nationality, all of the Company's address at Clydesdale Engineering Works, Cardonald, l Renfrewsbire, do hereby declare the nature of this invention and in what manner the same is to be performed, to be particularly described and ascertained ii and by the following statement:-
This invention relates to improvements in pressure fluid safety valves.
A safety valve according to the invention includes a valve element of pot form fitted with a loose lid memoer and with a ported loose cylindrical -sleeve closely surrounding the valve pot, there being provided between the valve element and the sleeve an annular recess which first receives pressure fluid released by the valve element where ' high-lift " travel is imparted to the valve element, and from which pressure fluid is admitted into the interior of the pot whereby to displace the lid member into sealing engaageiient with a guide penetrated by an externally-loaded spindle a.cting on the valve element.
The valve spindle guide is preferably constituted by a blush provided with a splined, fluted or otherwise machined bore devised to afford substantially frictionless guidance for the valve spindle.
The sleeve rests at its lower end on a valve seat memlber and is adapted, sluhi it stick to the valve element, to lift with the valve element and to afford outlet between its lower end and the seat memlber for release of pressure fluid.
A pressure fluid safety valve accordimt, to the invention is illustrated in the accompanying drawing in which Fig- 1 i' a vertical axial section and Fig 1 2 a detail transverse section on the line TI-II of Fig 1.
The safety valve shown include a 76 se fety valve element 10 which is adapted to perform so-called " high-lift travel in opposition to the action of a spring'1 1 located externally of the safety val-e chest 12 and actin,, on the valve ulemiiiet 75 throuah the miediumil of a preferablly uprig,8 ht spindle 13 on the lower end of whhbih the valve element 10 is centered.
The valve element 10 co-operates with an orificed seat mem ler 14 secured witili 8 ( the valve chest 12, the central portion of the valve element converging downwardly into the seat orifice 14 ' and( presenting' a conical socket 10 ' for receptioll of a conical nose 13 ' on the lower 85 end of the spiadle 13 Tjie valve element is unitary with an upstanding cylinidrical m-all 102 forining' therewith a pot structare loo^,ely fitted with a lid member loosely,Jeneirated by the spindle 13 90 and rlcding a cylindrical skirt or boss 1 15 ' which depends and is a sliding fit within the bore of the pot The lid mem Ler 15 is formed with a peripheral flange 15 which overthans a, peripheral 95 flange 10 " on the upper end of the pot, the flaic,,e 15 being' provided on its xrn'erside with an annular ridge 153 which rest.
on the upper end of the pot Pressitrfluid is adapted to Tje admitted into ille 10 10 interior of the pot as hereinafter described, when the valve element 1 ( is unseated wherebyv to force the lid memb)er 115 upwardly and to cauise al annillar sealing' fa(e 15 ' on the pp'ei 105 surface thereof to enter into sealin,engatemeut will an annular ahl irn eiil sealmig face 161 on the lower or innei endi of a valve spindle g uide bush 16 secured in ihe cover 12 'r of the valve chest 12, 110 said l ush lbeint forimed with a sidlined.
fluted, or otherwise mar hje e '16 ' devi-sed to afford linited coufact on v flor g Cuidance therethrough of the spindle 1:, so that the spindle may slide in the 115 a 532,599 bush with minimum frictional restraint.
Closely surrounding the pot is a laterally-ported loose cylindrical sleeve 17 which rests at its lower end on the valve seat member 14 The lower portion of the sleeve 17 surrounds the interen-aging valve and seating faces and forms the outer boundary of an annular recess hereinafter referred to.
The exterital diameter of the valve face is s, hstantially less than the external diameter of the pot and there is formed in the valve element 10 around and above the valve face 103, an annular recess 18 which is bounded on its external circumference by the lower portion of the sleeve 17 and which first receives pressure fluid released by the valve element 10 A small orifice 19 provided in the valve element 10 connects the recess 18 with the interior of the pot The seat face 142 is surrounded by an annular cavity 2 ( O forming part of the recess 18 and O oiiiided on its outer periphery by all o 25 annular rim 21 upstanding from the seat rember 14 into the recess 18 The lower end portion of the sleeve 17 is so constricted as closely to surround the rim 21.
The ports 22 in the sleeve 17 are pitched around the circumference thereof and are located above the level of the circulmferential edge 23 of the valve element 10 which defines the upper limit 6 f the recess 18.
3,5 Ill operation, when the fluid pressure on the upstream or under side of the valve element 10 is such that the valve element 10 is unseated, the released pressure fluid enters the recess 18 and exercises further thrust in valve-opening direction on the supplementary area of the valve element exposed within the recess 18, so that the valve element 10 shoots rapidly to " high-lift " position; in which position the valve element unmasks the ports 22 and thus affords free outlet for the released pressure fluid.
In the initial opening movement of the valve element 10, pressure fluid also flows from the recess 18 through the orifice 19 into the pot and forces the lid member 15 upwardly until the sealing face 15 ' thereon engaoes the sealing face 161, and thus prevents escape of fluid through the Sa spaces 16 ' between the spindle 13 and the bush 16 into the space 24 above the valve chest cover 121 which houses the valveloading spring 11 When the valve element 10 closes, the lid member 15 drops back into its normal position on top of the pot Should the sleeve 17 stick to the circumference of the pot for any reason, t'be sleeve will rise with the valve element 10 and the released pressure fluid will have free egress 65 through the annular gap formed between the seat member 14 and the now elevated lower end of the sleeve 17.
As will be understood, the construction is such that the valve element 10 is 70 ensured maximum freedom for movement and " high-lift " operation is obtained without the use of an auxiliary piston.
Further, since the released pressure fluid enters the annular recess 18 prior to 76 release through the sleeve ports 22, the valve functions with minimum noise and with minimum deleterious percussive action on the waste steam pipes or passages 80 Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we