US1668075A - Safety valve - Google Patents

Description

May 1, 192s. 1,668,075

l B. J. HELLWIG SAFETY VALVE n Filed June 30. 1920 2 Sheets-Sheet 2 fr ""WA .l

/A/Vf/V/a' Mw )M117 BY Patented May 1928.

UNITED lSTATES PATENT oEFlcE.

BENNIIAND J. 'HELLwIa or CINCINNATI, oHIo, 'nssmNon 'ro'rnn LUNxENIIanEan.

" comrANY, or CINCINNATI, o1=IIo,uA` conronArIoN or onro.

SAFETY VALVE. f

. Application mea :une so, 1920.` suur No. ataca.l l

i `Myinvention relates to safety valves of the t pe termed commercially .pop valves whic are employed for the mostpart in` steam boilersgfor the release Yof steam there- 5 from uponexcessive pressure.

`With boilers of large capacity where uantities of steam must escape to `prevent l angerous over pressures, it. has been the practice, to use one large or a `number of l smaller safet valves of `moderaterelieving capacityaan close regulatiom `Attempts have been .made to reduce Vthe size or number of such valves by providing a construe-t` tion through which much` reater; quantities l of steam are dischar ed. uring therelievf` ing operation, but al such attempts have been only partly successful in that while discharge capacities were greatly" increased, the closeness of` the regulation waslwldened in proportion with consequent serious and unnecessary loss of steam` during the blowr in period.

ence, the problem involved ina modern` pop safety valve is to rovide for a` sufficiently rapid release o excessive pressure and at the Vsame time for a releasewhichwill sharply close ata pointbelow the pressure at which the valve is set, with as little drop belowthat point as possible7 with the valve operating smoothly and positively.

These objects and other advantages to `be noted I accomplish by that certain construction and arrangement of parts to be hereinafter moreV specifically pointed out and claimed.

lIn thedrawings, l Figure 1 is a longitudinal section through `my new valve in one form thereof. Y

Figurev 2 is a detail section .of the valve seat, and huddling chamber of the form of valve shown in Figure l, on a largerscale.

Fi ure 3 is a plan view of the blow-down re u ating ring.` Y

igure 4 is a partiallysectioned side eleve made accordingto my Figure 6 is a plan view of the regulating ring. i 5 Figure 7 is a section of the said ring on theline 7, 7, of Figure (i. 4

. Figure `8 ,is a longitudinalsection through the seat ring. l r t Figure 9 Aisa bottom plan view of thels valve disk. vIt should be noted of` my invention that the essential basis thereofis to provide a` huddling chamber for the valve `which dueV to its special characteristics brings about the yrise and fall 01E-the valve, there being no essential difference between my valves and those of the prior art except with rela- A tion to this huddling chamber and the parts which surround it. In one of the instances the huddling chamber `is formed between the valve disk and the .seat ring, the seat ring having an adjustingl ring `in connectionf therewith.Y In the other instance the` seat.`

rin has mounted thereon an adjustin ring 70 which itself forms a portion ofthe hu dling chamber. I will briefiy refer tothe normaltsafety orfpop valve parts which I employ. There is the body l, thel top 2 mounted thereon, 75 the inlet port 3 and the discharge port 4 being in the bod There is the stem 5 under` control of tiie. spring 6, which sprin presses downwardly on the spring holder at the end of thestem. `8" The adjusting screw8 threaded into the top of the valve adjusts thepressure on the spring and thus the point at which the valve will pop off. I prefer that the spring be a long one, which will, in my opinion, add to the Value of a valve made according to my invention'.l l t The valves in both instances have disks 9 having guiding win orwebs 10, samebeing widened at the ceas at'll to provde90 ample guide surface withinthe seat ring 12.` In each instance also the seat ring is thread-` ed into thebody and is formed with a seat 13 for the valve disk. The disks in both cases are formed with i seat bearings 14 and at the upper end there-` of have a lip that depends around the edge of the disks to form a recessed chamber 16. The spring holders 7 on the ends of the stems find a freely rockin seat within the concavity at the top o the valve disks.

Taking now the exemplary embodiment of m invention shown in Fi ures 1 to 4, it will be noted that the seat ring is externally threaded to receive a special shaped regulatin i rin 17, this regulating ring being ad-A justa le diie to its threaded mounting and adapted to be held in adjusted position'by the regulating ring screw 18, threaded into the valve body. The u per portion ofthe regulating ring' i is forme with an annular, upwardly and inarming the hy wardly extending sleeve 19, the inner wall 20 of which has a conical upward slantto the axiso the valve disk and its seat. The angle which the said inner wall forms with relation to the angle of the valve seat should be according to my experience nearer 90 degrees to the-path of the escaping steam than 45 degrees.

No exact an le is prescribed, however, ex-

cept that the s ope of the wall 20 should bel directed towards the inner curve or slo e 21 of the lip recess; and the height o the sleeve 19 forming this angle should be such as to substantially close with or approach closely to the outer slope 22 of the lip recess 16 to produce a .reaction effect.

In fact the forms of the invention with which I have had greatest success have been ones in which the huddling chamber has beenin` substantially the form of avright angie triangle in cross section with the wall 20 tenuse. I have now ound by extensive ex riments that the formation of a hud ling chamber above the valve seat, by means of a sleeve with conical interior, and a recessed disk lip above it, that the resulting inwardl and'. upwardly impelling steam flow with its consequent reaction produces much more ecient action than any other known construction. By this I mean that when poping the disk is lifted from its seat yto a eightfar exceeding ordinary practice, that it operates smoothly due to the centralizing eect of the steam flow and closes down gradually with a final closure which, while sharp, is no more injurious than the seating of less'eflicient valves. Perhaps the greatest gain accomplished by my peculiar constructionis that pop valves so made can be re lated to perform their function of relieving excess pressure with less wastage of steam than has heretofore been thought possible' in valves of high. relieving capacity.

The amount of the blow-down or steam relief is regulatable within limits by adjusting the ring 17 up or down according to conditions.

In the modification shown in Figures 5-9, the valve disk is the same, but the seat ring is formed with an upwardl and inwardly extending sleeve 23, which 1s formed at an angle, as to its inner wall, as in the case of the regulating ring of the first described form, and thus forms the outer wall of the huddling chamber of the valve. Y

This sleevehns an annular series of holes 24 therein which are controlled by means of a regulatin ring 25, threaded onto the seat ring anda pted in its various positions to close o' prtlons of the holes against escape o f steam. The preferred form of regulating ring 25 has an inwardly extending lip 26 which wipstln enter-surface of the seat ring sleeve.

`las is ep arent the Manoa-betweenthe l two forms 1s inY the method of udjustinle;

amount of escape of isteam from the dling ehamber,'this being controlled in the first formby the amount of escape around'.

the to `of the huddling chamber, and in the secon form by the amount of escape throu h the side walls of the huddling chamber, action of the valve beingY about the same in either case.

I desire to include within-the claims that follow the full range o equivalent structures familiartothoseskilled in the valve making arttl 1 A Vertical outer walls for huddling chambers are in use' at the Yprt time, and in some instances these walls arelformed with smallpockets at the base, to. form a sort' of l. In a safety valve, the combination with a valve seating member, a resiliently held valve disk, andY an adjusting ring, said adjusting rin having inwardly and upwardly sloping wa lsinterceptng the path Vof steam across the seat, and the valve disk having an outwardly and downwardly turned edge oerhanging theA adjusting ring on its outer e ge.

2. In a safety valve, the combination with a valve seating member, a resiliently held valve disk, and an adjusting rin said ad` justing rin* having inwardly n upwardly sloping wa lsinterceptingV the path of steam across the seat, and the valve disk having lm lll outwardly land downwardl turned edge overhanging the adjusting ring on itspouter edge and means for adjusting the amount of escape from the chamber formed by said disk and said adjusting ring.

3. In a safety valve, the combination with a valve seating member, a resilient valve disk, and an adjusting ring, said adjusting ring having inwardly and upwardly sloping walls intercepting .the path of Asteam across l0 the seat, and the valve disk havin an outwardly and downwardly turned e ge overhanging the adjusting rmg on its outer edge,

j and means for adjustably positioning the adjusting Aring to determine the normal o nl5

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