NZ239796A

NZ239796A - Fluid control valve with flow check arrangement which extends upstream of a fixed closure seal to control water hammer

Info

Publication number: NZ239796A
Application number: NZ23979691A
Authority: NZ
Inventors: Alfred Hirzel
Original assignee: Apex Valves Limited Formerly A
Priority date: 1991-09-13
Filing date: 1991-09-13
Publication date: 1994-10-26
Also published as: AU653422B2; AU2127992A

Description

<div class="application article clearfix" id="description"> ; 7 Q u / 7 9- ✓ w , - ' \ 0~, V P F 5 - , y/O Code 1050 if ,7 Fee $260 I! NEW ZEALAND Vt> PATENTS ACT 1953 V t N-> V No. 239796 x Priority Date; 13 September 1991 COMPLETE SPECIFICATION e of cf applicant NG'i CF r ex IMPROVEMENTS IN OR RELATING TO VALVES WE &?EX - ENGINEERING LIMITED of 1 Waikaukau Road, Glen Eden, Auckland, New Zealand, a New Zealand company, 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- 2 This invention relates to fluid control valves and in particular flow check means for incorporation in a valve intended for controlling pressurised liquid flows to reduce, if not eliminate, vibrations and consequential noise arising during closure of the valve. A noise problem can arise with valves controlling liquids under pressure such as a float operated valve controlling a mains pressure water supply to a reservoir, tank or similar. In some cases the closing can cause water-hammer and/or other vibrations being set up causing undesirable noise as the valve closes. An intention of this invention is to provide means for inclusion in such a valve or a valve incorporating such means which will at least reduce the likelihood of such noise occurring. According to a first aspect of this invention there is provided a fluid control valve including a fixed closure seal thereof and separate flow check means extending upstream thereof as to surround, in adjacent and gradually increasing spaced relationship therewith, a sealing element of a dynamic closure means of the valve to form a gradually restricting flow passage through the valve as the closure means approaches a closure mode with the sealing element in impingement with the seal the flow check means being maintained in axial alignment with the dynamic closure means by fixed location against a body of KJ/ 10 the valve. According to a second aspect of this invention there is provided a fluid control valve as described in the preceding paragraph wherein the closure means is in the nature of a plunger primarily operated by a float controlled lever but which also incorporates a flow impeding protrusion thereon whereby flow pressure on the flow impeding protrusion assists closure of the valve. In further describing the invention reference is made to the accompanying drawings wherein: Figs 1 and 2 are cross-sectional views (Fig 1 in an open 15 mode and Fig 2 in a closed mode) of a preferred embodiment of valve and incorporating flow check means as a separate component, and Figs 3 and 4 are enlarged cross-sectional views of two 20 alternative valve structures incorporating flow check means in accordance with this invention, components and features common to those in the preferred embodiment being correspondingly numbered. 25 Referring in particular to Figs 1 and 2 a body 1 preferably moulded of a plastics material is of a generally cylindrical form with a removable end cap 2 at • 4 2397 one end and with a radially extending inlet port 3 forming spigot partway along the body 1 . An outlet port 5 is formed centrally through the end cap 2 and an annular seal 6 is mounted within the end cap 2 to extend 5 about the outlet port 5. At an end of the body 1 distal of the end cap 2 the body 1 is of a reduced diameter to form bore section 1a, the 5 0 ? 0 =7 (\ <- o / y • 5 10 15 20 reduction also forming a shoulder 7. An internal annular wall or skirt 8 extends from the shoulder 7 concentrically into the main or larger diameter interior of the body 1 for approximately one third the depth thereof. A plunger 9 like element comprises a main cylindrically section open at a valve seating end 9a. At the other end 9b the plunger 9 is diametrically reduced in size to fit within the end 1a of the body 1. Sealing means such as an "0M-ring 10 are mounted in an annular groove formed in the external wall of the major diameter part of the plunger 9 adjacent to the reduced end section 9b thereof. In assembly the major diameter section of the plunger 9 fits within a bore 11 formed by the annular skirt 8 with the "0"-ring forming a seal therewithin. The reduced diameter end of the plunger 9 locates in the reduced bore section 1a of the body. A float arm 12 is pivotally attached, such as by pin 13, to the body such that the inner end thereof terminates within the reduced bore section 1a. The inner end of arm 12 impinges onto the end of the plunger 9 with appropriate movement of the float arm 12 to displace the plunger 9 toward the outlet port 5 of the valve body 1. ( V / 3 9 7 9 6 6 Referring in particular to Fig 1, the length of the plunger 9 is such that with such displacement the open end or lip 9a of the plunger 9 impinges onto the seal 6 to close the valve. Preferably a small external annular 5 shoulder 14 is formed on the plunger 9 adjacent the sealing lip or end 9a thereof such that liquid pressure within the valve acts thereon to assist closure of the valve. 10 Flow check means 15 are provided to extend about the junction between the sealing lip 9a and seal 6 when a closure mode is approached. The flow check means provides for a gradual restriction of the flow passage (indicated by arrows 3 and 5) and it is found that this 15 tends to reduce the likelihood of unwanted vibrations and consequential noise. The flow check means 15 is disposed adjacently upstream of seal 6 with preferably the seal 6 acting as a base for 20 the flow check means 15. In a preferred embodiment as depicted in Figs 1 and 2 the flow check device 15 is formed as a separate component from the seal 6. The check device 15 is in the form of an annular ring, preferably moulded from suitable plastics material and 25 having an upwardly and outwardly inclined wall 16 which, in situ, extends upstream of the face of the seal 6. The diameter of the inner and lower end of wall 16 is 3 9 7 9 6 7 marginally larger than the diameter of plunger 9 and may terminate in a short axially extending section abutting the seal 6. 5 Preferably an annular lip 17 is provided on the outside of the flow check ring 15 such that when the ring rests on the seal 6 the lip 17 is captivated by the mountings of end cap 2 to the body 1. Preferably detent projections 18 are also formed within the body to limit 10 any displacement of the flow check ring 15 should, for example, the locating lip 17 fracture. Referring to Fig 3, in one alternative form the flow check device 15 is integrally formed with the seal 6. In 15 this form the sealing face of the seal 6 incorporates an annular groove 19 in which the plunger 9 seats in the closed mode. The outer wall 16 of the groove 19 is inclined upwardly and outwardly and is disposed to adjacently surround the sealing lip 9a as it approaches a 20 closure mode with the seal 6 to thus check the flow of liquid. Referring to Fig 4, a further alternative form of the invention is described. In this case the sealing lip or 25 end 9a of plunger 9 seals within an "0"-ring seal 6 mounted in outlet port 5. The "0"-ring is mounted adjacently down of the shoulder 20 forming the upstream 239796 8 end of port 5. The corner of the shoulder is chamfered or similarly bevelled to provide an outwardly and upwardly extending face 16, to correspondingly reduce the flow path as a closure mode is approached. It will be appreciated by those skilled in the art that while this invention has been described by way of preferred embodiments and as part of a complete valve a flow check device in accordance with the invention could be provided as a separate element to be fitted to existing valves to enhance there operation as herein described. </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 9 239796 20 WHAT WE CLAIM IS:

1. A fluid control valve including a fixed closure seal thereof and separate flow check means extending upstream thereof as to surround, in adjacent and gradually increasing spaced relationship therewith, a sealing element of a dynamic closure means of the valve to form a gradually restricting flow passage through the valve as the closure means approaches a closure mode with the sealing element in impingement with the seal the flow check means being maintained in axial alignment with the dynamic closure means by fixed location against a body of the valve.

2. A fluid control valve as claimed in claim 1 wherein the closure means is in the nature of a plunger primarily operated by a float controlled lever but which also incorporates a flow impeding protrusion thereon whereby flow pressure on the flow impeding protrusion assists closure of the valve.

3. A fluid control valve as herein described with reference to the accompanying drawings. \ l2jc>- m4 '■ ROSS NEWNHAM </div>