NZ517764A

NZ517764A - Liquid tempering valve with control piston within diverter displaceable by temperature activation sensor

Info

Publication number: NZ517764A
Application number: NZ51776402A
Authority: NZ
Inventors: Alfred Hirzel
Original assignee: Apex Valves Ltd
Priority date: 2002-03-13
Filing date: 2002-03-13
Publication date: 2003-10-31
Also published as: AU2003200856B2; AU2003200856A1; ZA200301992B

Abstract

Diverter 14 functions to separate hot and cold water paths 3d, 4d and to direct water to opposing ends 7a, 7f of piston 7. These ends "open" or "close" on seats 16a, 5 of the valve body 1.

Description

<div class="application article clearfix" id="description"> P.F. 5 Code 1050 Fee: $250 NEW ZEALAND PATENTS ACT 1953 £ No. 517764 Priority Date: 13 March 2002 COMPLETE SPECIFICATION AN IMPROVED LIQUID CONTROL VALVE We, APEX VALVES LIMITED, a New Zealand company of 367 Rosebank Road, Rosebank, Auckland, New Zealand do hereby declare the invention for which We pray that a Patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: - 1 - INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 U MAR 2003 RKGKIVED N1366nzCAP.doc This invention relates to liquid control valves and in particular a valve for controlling the temperature of hot water at an outlet therefor. Such valves are often called tempering valves and that term is so used herein. Tempering valves are typically used in domestic and similar hot water supplies to ensure 5 the hot .water is supplied within a required temperature range. More particularly, it is considered desirable, that, on the one hand, the temperature within a domestic dwelling water-heating cylinder not be lower than a certain temperature, but on the other hand, that the temperature from an outlet, typically a tap, from the cylinder not be higher than a certain temperature. This desirability is in some jurisdictions reflected in regulations 10 relating to the provision of hot water supplies. In brief, the object is to ensure the temperature of the water within the cylinder is appropriate to prevent bacterial growth, in particular legionella bacteria, while ensuring the temperature of the water available from an outlet of the cylinder is limited to prevent injury such as from scolding. Typically the regulations require the cylinder temperature to not be lower than 60 degrees C and the 15 outlet supply temperature to be in the range of 45 degrees C to 55 degrees C. A problem can arise with the inclusion of such a valve in a hot water supply in that the flow rate therethrough can be reduced owing to a reduction in the volumetric through capacity available through some known tempering valves. An object of.this invention is to provide a tempering valve that will meet the above requirements. A further object of this invention is 20 to provide a tempering valve wherein the volumetric through capacity thereof is commensurate to that of the optimum conduits intended to be connected thereto. A further object is to provide the public with a useful choice. N1366nzCAP.doc 3 According to a first embodiment of this invention there is provided a liquid tempering valve broadly comprising a body containing a chamber with separate hot and cold inlet ports and a single outlet port joining thereto, a diverter sealingly mounted in the chamber to straddle the inlet ports and having hot and cold openings substantially in alignment with the 5 respective hot and cold ports to thereby create within the chamber diverging hot and cold liquid flow paths, an open ended hollow liquid control piston mounted within the diverter and displaceable therein by a liquid temperature activating sensor mounted in the outlet port, the piston being mounted between valve seats provided in the body and disposed adjacent to and co-operative with the ends of the piston to form valves, one valve 10 controlling the hot liquid path and the other valve the cold liquid path whereby, in use, with an activating increase in liquid temperature in the outlet, the sensor displaces the control piston in one direction to decrease the capacity of the hot liquid path and increase the capacity of the cold liquid water path and vice versa to thereby introduce more or less respectively cold liquid into the hot liquid in the outlet and tend to maintain the temperature 15 thereof within a required temperature range. According to a second embodiment of this invention, there is provided a liquid tempering valve as described in the preceding paragraph wherein the hot and cold ports are disposed substantially in alignment opposite one another and the sealing of the diverter within the chamber is about the periphery thereof at an angle to both the line of the hot and cold ports 20 and to the line of displacement of the control piston. According to a third embodiment of this invention there is provided a liquid tempering valve as described in either of the two immediately preceding paragraphs wherein the INTELLECTUAL PROPERTY OFFICE OF N.Z. 2 0 AUG 2003 RECEIVED NI366nzCAP.doc 4 sealing means comprises an "O'-ring mounted in a groove formed about the exterior of the diverter with the hot and cold inlet ports positioned transversely opposite one another and the outlet port disposed therebetween in a "T" configuration, the diverter being mounted in the chamber with the hot opening thereof disposed adjacent to the outlet port and the diverter and the piston have shoulders partway along their lengths, the shoulders cooperating to provide a space between the piston and the diverter and to retain separating sealing means between the shoulders, the separated spaces forming part of the cold and hot inlet paths. In further describing the invention reference is made to the accompanying drawings wherein; Fig. 1 is a side view, and Fig. 2 is an end view, and Figs. 3, 4 and 5 are cross-sectional views on lines A-A, B-B and C-C respectively on Figs. 1 and 2, and Fig. 6 is a perspective view of a diverter component used to contain a control piston component depicted in Fig. 7, and Figs. 6a and 6b are cross-sectional views on lines D-D and E-E shown on Fig. 6c, and Fig. 7 is a perspective view of a control piston for housing the diverter depicted in Figs. 6, and Fig. 7a is a cross-sectional view of the control piston on line F-F shown on Fig. 7b. NI366nzCAP.doc A body 1 is preferably forged from a suitable metal such as brass to form a chamber 2 with a cold inlet port 4, a hot inlet port 3 and an outlet port 5 joining therewith. Preferably the body 1 is of unitary form and includes spigots 3a, 4a and 5a associated with the corresponding ports 3, 4 and 5. In use a non-return valve 4b is preferably coupled to the 5 cold inlet port 4. Preferably the inlet ports 3 and 4 are positioned substantially in line with one another, that is, through transversely opposite sides of the section of the body 1 forming chamber 2. Preferably the outlet port 5 is positioned intermediately of the inlet ports 3 and 4, through a lower (referring to the drawings which depict a preferred mounting disposition for the valve) section of the body 1. The associated spigots 3a, 4a and 5a are thus disposed 10 in a "T" configuration. Preferably the volumetric capacity, that is the bore size, of the inlet ports 3 and 4 and the spigots 3a and 4a are commensurate to those of optimum sized conduits (not depicted) to be joined thereto. Body 1 preferably includes an upstanding annular shaped wall la opposite outlet spigot 5a, the void 2a defined by the wall la joining with and forming part of the chamber 2. A cap 11 fits on wall la and removal thereof 15 provides access to chamber 2 for the mounting therein of the other components of the valve. As described in more detail below, a water temperature activated sensor 6, (of known form) is mounted on and primarily acts against a main spring 8 mounted within the outlet port 5. The sensor 6 displaces (upwardly and downwardly as depicted) a water control piston 7 20 (depicted in detail in Figs. 7, 7a and 7b) fixed to the sensor 6 and slidingly mounted in a cage like diverter 14 (depicted in detail in Figs. 6, 6a-6c) sealed in the chamber 2. Sensor 6 expands and contracts dependant upon the temperature of water acting on the sensor 6 in outlet spigot 5a. In turn this correspondingly alters the position of control piston 7 within the diverter 14 and relative to an upper valve seat 16a and a lower valve seat 5a formed as N1366nzCAP.doc 6 part of the inner wall of the chamber 2. This displacement alters the ratio of hot to cold water flowing through the chamber 2 and thus the temperature of water discharging through the outlet port 5. Under normal working conditions this displacement is only over a range of about 1 to 1.5 millimetres. It is because of this minimal clearance that the drawings 5 depict the valve with the hot inlet path, indicated by broken line 3d, fully open and the cold inlet path, indicated by broken line 4d, fully closed. Fig. 6 and Figs. 6a-6c depict in detail diverter 14 which is mounted in the chamber 2 to slidingly retain the control piston 7 within a bore 21 of the diverter 14. Diverter 14 is preferably made from a suitable plastics material and has a cylindrically shaped wall 14a of 10 a cage form. Diverter 14 is open ended, as indicated by arrows 14b, with an internal annular shoulder 20 partway along the bore 21 thereof. Means are provided for sealing the diverter 14 in the chamber 2. Preferably the sealing means comprise an "0"-ring (not depicted for clarity) retaining channel or groove 22 formed about the exterior of the wall 14a thereof. The channel 22 and thus the sealing means mounted therein are disposed at an 15 angle to the longitudinal axis of the diverter 14. More significantly, as will be apparent from the following description, it follows the sealing means is correspondingly off-set relative to a line of displacement of the piston 7 mounted in the diverter 14. Preferably the channel 22 is disposed at 45 degrees to that longitudinal axis and extends from adjacent a first end to adjacent a second end of the diverter 14. (Referring to the preferred mounting 20 disposition of the valve and as depicted, hereinafter the first end will be called the upper end 23 and the second end the lower end 24.) The groove 22 thus crosses over at a 45 degree angle an annular section 14d of and partway along the diverter wall 14a and which carries the shoulder 20 internally thereof. Nl366nzCAP doc The section of the diverter wall 14a bounded by the groove 22, the associated lower end 24 and the wall section 14d associated with the internal shoulder 20 is absent except for pillars 14f and forms opening 3b through the wall 14a. In corresponding manner, the section of the diverter wall 14a bounded by the groove 22, the associated upper end 23 and the wall 5 section 14d is also absent and forms opening 4b through the wall 14a. The openings 3a and 4a are thus off-set upwardly and downwardly of one another at an angle opposite to that of the groove 22. Preferably the shoulder 20 is positioned mid-way along the diverter 14 and the associated wall section 14d extends marginally downward thereof toward the lower end 24. This provides that hot water opening 3b is smaller than cold water opening 4b, the 10 capacity of opening 3b preferably being about 20% less than that of opening 4b. Referring in particular to Fig. 5, in assembly of diverter 14 within chamber 2 openings 3b and 4b are substantially aligned with their corresponding inlet ports 3 and 4. With such assembly an "0"-ring (again for the sake of clarity, not depicted) within channel 22 seals against the internal face of the chamber 2 and separates, with respect to the chamber 2, the 15 hot and cold inlet ports 3 and 4 together with their respective openings 3a and 4a from one another. Preferably lugs 19 are provided on the diverter 14 to clip under co-operative ledges, for example the upper extremities of the inlet ports 3, 4, and correctly position the diverter 14 in the chamber 2. The preferred positioning provides that the hot opening 3b is disposed adjacent to the outlet port 5. 20 Fig. 7 and Figs. 7a and 7b depict in detail control piston 7 which is slidingly mounted in the bore 21 of the diverter 14. Control piston 7 is of an opened end hollow cylindrical form with an internal radially disposed webbed wall 23 supporting a central column 7d extending down from, in assembly, a lower end 7a thereof. The column 7d has a bore 7c in and NI366nzCAP.doc 8 through which sensor 6 is mounted. The lower end of the column 7d seats against an external shoulder 6a provided on the sensor 6. An external annular shoulder 7b is formed on the control piston 7. The extent of the projection of the shoulder 7b corresponds to that of shoulder 20 from the surface of bore 21 on diverter 14. In assembly of the control piston 5 7 in the bore 21 of the diverter 14, the shoulders 20 and 7b co-operate to provide a sliding fit between the diverter 14 and control piston 7 and in so doing also space the remainder of the outer surface of the control piston 7 adjacently inward of the surface of the bore 21. This spacing forms part of the flow paths 3d and 4d and directs the incoming hot and cold water about the upper end 7f and the lower end 7a of the piston 7. With this assembly an 10 "0"-ring 26 is provided as a separating seal between shoulder 7b and shoulder 20. A safety spring 9 together with an associated poppet 10 are mounted within a spindle 17. In turn spindle 17 is adjustably mounted in a cylindrical shaped bonnet 16 mounted within the section 2a of chamber 2 opposite sensor 6. As typically "factory set" about a l-2mm gap 25 is provided between the head of the sensor 6 and the poppet 10. Safety spring 9 is 15 of high compression and, other than for safety purposes as discussed below, it and poppet 10 can be considered immovable. Preferably an inner end of bonnet 16 forms valve seat 16a against which the upper end 7f of piston 7 impinges to close the cold water path 4d this also being typically the "factory set" mode. Adjusting spindle 17 enables the spacing of gap 25 to be altered and, as will be apparent from the following operational description, 20 thereby the temperature range in which the valve operates. Preferably "0"-ring seals 15 are provided between bonnet 16, body 1 and spindle 17. Sensor 6 expands with increased temperature and contracts with decreased temperature. In operation, commencing with a "factory set" mode thus hot water in the outlet 5 will result NI366nzCAP.doc 9 in the sensor 6 extending upwardly and contacting the "immoveable" poppet 10. The sensor 6 and the piston 7 will thus be forced downwardly against the main spring 8. This action decreases the gap between the lower end 7a of the piston 7 and the valve face forming section 5a of the wall of the chamber 2 and increases the gap between the upper 5 end 7f and the associated valve face 16a. Thus the hot inlet path 3d tends to "close" and the cold inlet path 4d tends to "open", that is the ratio of hot to cold water in the outlet 5 is reduced lowering the temperature of the water in the outlet 5. As the temperature sensed by the sensor 6 decreases the opposing action takes place. Thus the ratio of cold water to hot water is adjusted to maintain the temperature at the outlet port 5 within the required range. 10 Should a malfunction, that is excessive water temperature in the outlet 5, occur the sensor 6 will continue to expand displacing the piston 7 downwardly until the hot water path 3d is closed with the closing of piston end 7a against valve seat 5a. It may be that the temperature increase is excessive causing abnormal expansion of sensor 6. In such case the expansion will overcome the resistance of safety spring 9 and will thus be taken up by 15 compression thereof preventing "self-destruction" of the sensor 6. </div>

Claims

<div class="application article clearfix printTableText" id="claims"> WHAT WE CLAIM IS 10

1. A liquid tempering valve broadly comprising a body containing a chamber with separate hot and cold inlet ports and a single outlet port joining thereto, a diverter sealingly mounted in the chamber to straddle the inlet ports and having hot and cold openings substantially in alignment with the respective hot and cold ports to thereby create within the chamber diverging hot and cold liquid flow paths, an open ended hollow liquid control piston mounted within the diverter and displaceable therein by a liquid temperature activating sensor mounted in the outlet port, the piston being mounted between valve seats provided in the body and disposed adjacent to and co-operative with the ends of the piston to form valves, one valve controlling the hot liquid path and the other valve the cold liquid path whereby, in use, with an activating increase in liquid temperature in the outlet, the sensor displaces the control piston in one direction to decrease the capacity of the hot liquid path and increase the capacity of the cold liquid water path and vice versa to thereby introduce more or less respectively cold liquid into the hot liquid in the outlet and tend to maintain the temperature thereof within a required temperature range.

2. A liquid tempering valve as claimed in claim one wherein the hot and cold ports are disposed substantially in alignment opposite one another and the sealing of the diverter within the chamber is about the periphery thereof at an angle to both the line of the hot and cold ports and to the line of displacement of the control piston.

INTELLECTUAL PROPERTY OFFICE OF N.Z.

2 0 AUG 2003 RECEIVED

N1366nzCAP.doc

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3. A liquid tempering valve as claimed in either claim one or claim two wherein the sealing means comprises an "O'-ring mounted in a groove formed about the exterior of the diverter.

A liquid tempering valve as claimed in any one of three preceding claims wherein the hot and cold inlet ports are positioned transversely opposite one another and the outlet port is disposed therebetween in a "T" configuration, the diverter being mounted in the chamber with the hot opening thereof disposed adjacent to the outlet port.

A liquid tempering valve as claimed in any one of the four preceding claims wherein the diverter and the piston have shoulders partway along their lengths, the shoulders co-operating to provide a space between the piston and the diverter and to retain separating sealing means between the shoulders, the separated spaces forming part of the cold and hot inlet paths.

A liquid tempering valve as claimed in any one of the five preceding claims wherein the sensor expands and contracts with temperature change, the piston being fixed thereto as to be displaced therewith, the sensor being mounted on and primarily acting against a spring mounted in the outlet.

7. A liquid tempering valve as claimed in claim 6 wherein a safety spring and associated "immovable" poppet as herein described are mounted in the body 20 opposite the sensor, expansion of the sensor impinging onto the poppet and causing the sensor and piston to displace against the spring.

4.

5

5.

10

6.

15

Nt366nzCAP.doc

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8.

5

9.

A liquid tempering valve as claimed in claim 7 wherein the safety spring and poppet are mounted in a spindle in turn adjustably mounted in a bonnet mounted in an upstanding wall forming part of the chamber, the hot liquid path valve seat being formed on the internal face of the chamber adjacently about the outlet and the cold water path outlet seat being formed on the inner end of the bonnet.

A liquid tempering valve as claimed in any one of the eight preceding claims wherein the body is forged from a suitable metal and a removable cap is provided to enable access to the chamber and thereby mounting of the other components within the chamber.

A liquid tempering valve substantially as herein described with reference to the accompanying drawings.

2^v~>

s

15 NEWNHAM & CO

LIMITED

NI366nzCAP.doc

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ABSTRACT

A liquid tempering valve to control the temperature of a hot water supply to within a required temperature range. A valve body 1 has hot and cold water inlet ports 3, 4 feeding through a chamber 2 of the body 1 to a common outlet port 5. Within the chamber 2 a 5 control piston 7 is mounted within a water diverter 14 having hot and cold openings 3a, 4a that are associated with the respective hot and cold ports 3, 4. The diverter 14 separates the hot and cold inlet paths 3d, 4d and directs the incoming water about opposing ends 7a, 7f of the piston 7. The ends 7a, If of the piston 7 "open" and "close" on valve seats 16a, 5a formed in the chamber 2. A water temperature sensor 6 is mounted on and biased by spring 10 8 within the outlet port 5 and slidingly carries the control piston 7 within the diverter 14. Water temperature change in the outlet 5 activates the sensor 6 which in turn displaces the piston 7. Displacement of the piston 7 in one direction increases the capacity of the hot water path 3d and decreases the capacity of the cold water path 4d and vice versa. Consequently the volumetric ratio of hot to cold water feeding to the outlet port 5 is altered 15 as is the temperature of the resultant mixture. Should an overheating malfunction occur the hot inlet path 3d will close and a safety spring 9 will take up excessive expansion of the sensor 6 to prevent self destruction.

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