US 3724753 A
A pressure and temperature relief comprising an upper and lower hollow bodies secured together with the lower body containing a temperature responsive bellows assembly being adapted for insertion into a boiler or other hot water storage vessel and having an inlet into the lower body. The upper attached hollow body has an outlet and a pressure relief valve which simultaneously functions as a temperature relief valve through the agency of an actuating rod connected to the bellows.
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Description (OCR text may contain errors)
United States Patent 1191 1 1 3,724,753 Thornton 1 1 Apr. 3, 1973  VALVE ACTUATING MEANS 2,553,347 5 1951 Work ..236/92 c 1,941,023 12/1933 Smith ..236/92 C  Invent g d Thommn Huddersfield 2,486,644 11/1949 (1105151511.... ..236/92 c I 2,497,201 2/1950 Banner ...236/92 c  Assignee: Samuel Birkett Limited, Heckmond- 217471802 5/1956 wike, Yorkshire, England 2,756,936 7/l956 Mueller ..236/92 C Filed; 1971 Primary ExaminerWilliam E. Wayner  AppL 112,640 Attorney-Bierman & Bierman 57 ABSTRACT  Foreign Application Priority Data 1 t A pressure and temperature relief comprising an Feb. 5, 1970 Great Britain ..5,58l/70 upper and lower hollow bodies secured together with the lower body containing a temperature responsive  US. Cl. ..236/92 C, 236/99 bellows assembly being adapted for insertion into a [5 lllt. Cl. boiler or other hot water storage vessel and having an Fleld of Search C, 99, inlet into the lower The pp attached hollow body has an outlet and a pressure relief valve which  References Cited simultaneously functions as a temperature relief valve UNITED STATES PATENTS through the agency of an actuating rod connected to the bellows. 2,351,190 6/1944 Carlson ..236/92 C 2,387,164 10/1945 McCarthy ..236/99 X 2 Claims, 1 Drawing Figure l! 42 Y 1 hf 44 l 1 5'4 1 4o 50 as l H 28 so i 4 /8 /e 494 M Z4/ i:7 in /o 1 A542,} ://8 /6 J; ASA
E a 245 i PATENTEnAPRs 1915 3,724,753
5 fl/ F d e/M44, 477040471.
VALVE ACTUATING MEANS This invention relates to valve actuating means and is particularly although not exclusively concerned with such means for actuating pressure relief valves on water boilers. The invention is primarily directed to water boilers and storage vessels used in commercial laundrettes, although the invention may be applied to other forms of water boiler.
It has been found, due to improper or inadequate safety mechanisms on such boilers, that the boilers have been overheating and in some cases have exploded due to the pressure relief/safety valves not being actuated and operated at the designed pressure and the invention seeks to obviate these and other disadvantages by providing actuating means which make the associated valve responsive not only to pressure but also to temperature.
According to the present invention, there is provided a valve actuating means adapted to be fitted to a water boiler or storage vessel, said valve actuating means comprising a hollow body having movably mounted therein a bellows assembly containing a volatile fluid which at a predetermined temperature of the water causes movement of the bellows, means connected to the bellows actuating an associated pressure relief valve. The pressure relief valve, due to the presence of the actuating means, is thus responsive to temperature as well as pressure.
An embodiment of the invention will now be described by way of example, reference being made to the accompanying drawing which shows an axial sectional elevation of means according to the invention.
Referring to the drawing, the valve actuating means of the invention is adapted to be located in a water boiler or vessel, the upper surface of which is indicated by reference numeral 20. As will be seen from the drawing, the valve actuating means comprises a lower hollow body 13 and an upper hollow body 12 removably secured together at said body 12 forming part of the pressure relief valve V. The lower hollow body 13 is closed at its bottom by an end cap 7 which may be permanently or removably secured in position, and the upper hollow body 12 carries a valve disc 1 of a pressure relief valve indicated generally by reference letter V.
The lower hollow body 12 carries and encloses a bellows unit in which is located a volatile liquid such as for example acetone. Secured to and extending upwardly from an end plate 15A of bellows unit 15 is a thrust rod 4 which is guided for vertical sliding movement by a base guide 14 of the upper body 12. The lower body 13 has an inlet port 13A and a port 14A is provided in the guide 14 to connect the interiors of the bodies 12 and 130. The upper hollow body 12 is provided with inlet ports 12A. The end plate 15A of the bellows unit 15 carries a filling tube 16 and a stop 18 for limiting the upward movement of the bellows unit.
The effective area of the bellows unit 15 should be the same as the bore in the seating of the valve disc 1, i.e., the upper hollow body 12, so as to ensure that variations in system pressure do not affect the operating pressure of the valve.
The pressure relief valve V is secured at 22 to the upper hollow body 12 which thus also forms the base of the valve. The valve disc is carried by a holder 24 which seats onto the upper extremity of the upper hollow body 12 the disc being secured to the holder by a circlip 2. Connected to the said hollow body 12 is a blow down ring 26 having an associated setting screw 28. The valve body 30, which as will be seen is hollow, has a guide 32 through which passes a spindle 34 having a head at its lower extremity which is secured to the spindle by a split pin 34A and which is adapted to maintain in contact with the valve disc 1 a spindle ball 36.
The spindle 34 has a coil spring 38 therearound, the spring being tensioned and set at the desired operating pressure, through the intermediary of an end plate 40, by an adjusting screw 42. The adjusting screw 42 operates in conjunction with a locknut 44.
The upper extremity of the pressure relief valve body 30 and the upper portion of the spindle 34 is covered by a dome 46 which is screwed at 48 to said body.
The pressure relief valve V has an outlet port 50.
It will be appreciated that whilst a particular form of pressure relief valve has been described and illustrated this could be replaced by other forms of valves.
In operation, water in the boiler or vessel 20 reaches a predetermined temperature and due to the inlet port 13A the heated water is able to surround and act upon the bellows assembly 15. Thus the heated water acts upon the volatile liquid in the bellows assembly 15 thus causing expansion of the latter. Such expansion of the bellows unit 15 causes the thrust rod 4 to rise upwardly (in the drawing) so that the thrust rod 4 may raise the valve'disc of valve V and so allow water to escape from the outlet port 50 of the valve V from within the interior of upper hollow body 12. After release of the water through the port 50, the coil spring returns the valve disc onto its seating on the upper hollow body 12.
Although the volatile fluid in the bellows unit 15 has been named as Acetone, it is obvious that many other types of fluid may be used, depending upon the temperature and pressure at which the fluid is required to move to cause movement of the bellows unit.
Thus it will be seen that with means according to the invention, a very simple and effective valve actuating means is provided which due to the inherent characteristics of the volatile fluid will ensure that the pressure relief valve is operated as soon as the temperature of the water in the boiler reaches its predetermined value.
1. Valve actuating means adapted to be fitted to a water vessel, said valve actuating means comprising a first hollow body having movably mounted therein a bellows assembly which is partly filled with a volatile fluid, said first hollow body having water inlet ports so that said bellows assembly is in direct contact with the water being controlled, said bellows assembly carrying a thrust rod which is guided for vertical movement by a base guide of a second hollow body to which the first hollow body is removably secured, said second hollow body forming part of a valve having a valve disc and forming a seat for the valve disc, the effective area of the seat being equal to the effective area of the bellows assembly, the first and second hollow bodies having a water flow port therebetween, said thrust rod being adapted to move as a direct consequence of the movement of the bellows assembly and acting directly on said valve disc against spring pressure so as to permit tube so that the volatile fluid can be inserted into the bellows assembly, said bellows assembly end plate also carrying a stop for limiting the upward movement of the bellows assembly.
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