NO20140840A1

NO20140840A1 - Dual plate check valve with an anti buckling system

Info

Publication number: NO20140840A1
Application number: NO20140840A
Authority: NO
Inventors: Jan Floberg
Original assignee: Jan Floberg
Priority date: 2014-07-01
Filing date: 2014-07-01
Publication date: 2016-01-04

Description

DUAL PLATE CHECK VALVE WITH AN ANTI BUCKLING SYSTEM

Fl ELD OF THE INVENTION

The present invention relates to a dual plate check valve assembly comprising an anti-buckling system for a stem and dise assembly. A rising stem provided by an outside screw and yoke system on the dual plate check valve assembly is provided to lift the dise assembly fuliy or partially clear of the seat in the radial direction versus the valve bore. The anti-buckling system, comprising an stem stopper provided on the end of the rising stem and a second rotation stopper pin in the dise assembly, is preventing buckling and deformation the valve assembly.

BACKGROUND OF THE INVENTION

The dise assembly on a dual plate check valve with rising stem typically comprises an upper hinge pin retainer, a lower hinge pin retainer, a rotation stopper pin, two dise memoers and one or muitiple springs and necessary grub screws or pins for holding the parts together in correct position. Reference is made to the Norwegian patent application no. 20130357 and PCT application no. SBSflMMH. describing dual plate checks valve with a rising stem. '<i?c>T-cP£<oH>-cif2M*ft

When axial force is applied by an operator onto the rising stem so that the dise assembly is moved to the lower position where the two dise memoers are aligned with the valve bore, the lower hinge retainer or the ends of the hinge pin and the rotation stopper pins will eventually meet the valve body. The reaction force on these parts will in this situation be equal to the axial force applied onto the stem by the operator, thereby the stem, the hinge pin and the rotation stopper pins may be exposed to buckling ca used by axial tension.

Hence, an improved dual plate check valve wherein buckling of the rising stem and other valve parts is prevented would be advantageous.

OBJECT OF THE INVENTION

An object of the present invention is to provide an improved and robust design of the stem on a dual plate check valve with a rising stem to prevent buckling and deformation of the internal and external parts.

SUMMARY OF THE INVENTION

Thus, the above described object and severat other objects are intended to be obtained in a First aspect of the invention by providing a dual plate check valve assembly for controlling the direction of flow in a piping system, comprising: pressure retaining enciosure comprising a valve body håving a valve bore and defining a valve seat; a rising stem configured to transversally disptace a dise assembly arranged inside the valve body, between a fowered position, wherein the dise assembly may control the flow through the valve bore and a raised position wherein the dise assembly is lifted at least partially clear of the valve bore and the valve seat, the dise assembly comprising two dise members adapted to engage with the valve seat to control the flow through the valve bore; wherein the dual plate check valve assembly comprises an stem stopper provided at an end of the rising stem configured to limit the axial movement of the rising stem so that dise assembly members are prevented from contacting the valve body when the rising stem is operated to the lowered position, thereby preventing buckling of the dise assembly members due to axial tensions from forces applied onto the rising stem by an operator.

Hereby undesirable buckling of the rising stem and other valve parts may be avoided.

In one embodiment the stem stopper may be fixed to the end of the stem by one or more screws, threads, welding or other suitabte methods, and the stem stopper is arranged to engage a yoke bushing or a yoke when the rising stem is operated to position the dise assembly in the fowered position.

Additionally the dual plate check vaive assembly described above may comprise a first rotation stopper pin and a second rotation stopper pin , the second rotation stopper pin being incorporated in the dise assembly, parallel to the first rotation stopper pin, a hinge pin and the rising stem for improving stability in the dise assembly and safeguarding against buckling and deformation of the dise assembly members due to forces applied from multiple directtons. Hereby increased

i protection against buckling of the dise assembly members is provided.

The stem stopper on the end of the stem and the rotation stopper pins prevent buckling and deformation of internal and external parts due to axial forces applied on the valve stem.

Further, the stem stopper may be larger in diameter than the rising stem and the position of the stem stopper on the rising stem is adjusted so that the stem stopper meets the yoke bushing or the yoke before the dise assembly meets internal part of the valve body when the stem and the dise assembly is operated

towards the tower position wherein the dise members aligned with the valve bore.

The extra rotation stopper pin wiii provide increased stability to the dise assembly when flow is going from the upstream side of the valve to the downstream side of the valve. If the stem stopper is missing or if it is adjusted in a wrong way, the extra rotation stopper pin will contribute as safeguarding against buckling of the dise assembly members.

Further, the stem stopper may be incorporated on the outside end of the stem.

Additionally, the stem stopper may be circular and mounted onto the stem by one or more screws, threads, weldings or other suitable methods. In one embodiment the stem stopper may also be an integral part of the stem.

BRIEF DESCRIPTION OF THE FIGURES

The anti-buckling system according to the invention will now be described in more detail with regards to the accompanying figures. The figures shows one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set. Figure 1 shows an expioded view of a rising stem dual plate check valve comprising a rising stem håving an stem stopper and a second rotation stopper pin, Figure 2 shows sectional drawing of a rising stem dual plate check valve illustration how the stem stopper ts mounted on an end of the rising stem, and the position second rotation stopper pin, and

DETAILED DESCRIPTION OF AN EMBODIMENT

Fig. 1 shows a dual plate check valve assembly 30 as described more in detail in Norwegian patent application no. 20130357 and PCT application no. SB&tittftl. The dual plate check valve assembty comprises an axial stem stopper 40 mounted on the rising stem 4 and first and second rotation stopper pins (10a, 10b). The disptaceable dise assembly 120 comprising two hinged dise members 12a, 12b, a hinge pin 9, an upper hinge retainer 8, a lower hinge retainer 11 and a spring memoer 14 is shown with the two rotation stopper pins (10a, 10b). Fig. 2 shows one way of mounting the axial stem stopper 40 on the rising stem 4, however the stem stopper 40 may be mounted in a number of other ways envisaged by the skilled person. The dual plate check valve assembly comprises a yoke 3 håving a yoke bushing 19, and in one embodiment the stem stopper is arranged to engage the yoke bushing 19 to top further axial displacement of the rising stem.

As seen from the figures the stem stopper has a diameter larger than the diameter of the rising stem, and the stem stopper engages the yoke bushing or the yoke before the lower hinge pin retainer or the ends on the hinge pin or the rotation stopper pins meets the internal part of the valve body. Hereby tensions that can resutt in buckling of the dise assembly members is prevented. Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention ts set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possibte elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageousiy combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possibte - and advantageous.

Pressure retaining enclosure 1

Bonnet flange 2

Yoke 3

Rising stem 4

Bonnet glands 5

Gland follower 6

Gland flange 7

Upper hinge retainer 8

Hinge pin 9

First rotation stopper pin 10a

Second rotation stopper pin 10b

Lower hinge retainer 11

Hinged dise members 12a, 12b

Bonnet gasket 13

Spring member 14

Valve seat 16

Bonnet bolts 17

Gland flange bolts 18 Yoke bushing 19

Stem bushing 20

Stem stopper 40

Stem stopper screw 41 Check valve assembly 30 Steering groove 101 Valve bore 102

Valve body 104 D-shaped flow paths 115a, 115b Dise assembly 120

Claims

1. A dual plate check valve assembly (30) for controlling the direction of flow in a piping system, comprising: - a pressure retaining enclosure (1) comprising a valve body (104) håving a valve bore (102) and defining a valve seat (16); - a rising stem (4) configured to transversaily displace a dise assembly (120) arranged inside the valve body, between a lowered position, wherein the dise assembly may control the flow through the valve bore and a raised position wherein the dise assembly is lifted at least partially clear of the valve bore and the valve seat, - the dise assembly (120) comprising two dise members (12a, 12b) adapted to engage with the valve seat to control the flow through the valve bore; wherein the dual plate check valve assembly comprises an stem stopper (40) provided at an end of the rising stem (4) configured to limit the axial movement of the rising stem 4 so that dise assembly members are prevented from contacting the valve body when the rising stem is operated to the lowered position, thereby preventing buckling of the dise assembly members due to axial tensions from forces applied onto the rising stem by an operator.

2. A dual plate check valve assembly (30) according to claim 1, wherein the stem stopper is fixed to the end of the stem by one or more screws, threads, welding or other suitable methods, and the stem stopper is arranged to engage a yoke bushing (19) or a yoke (3) or a hand wheel when the rising stem is operated to position the dise assembly in the lowered position.

3. A dual plate check valve assembly (30) according to claim 1 or 2, comprising a first rotation stopper pin (10a) and a second rotation stopper pin (10b), the second rotation stopper pin being incorporated in the dise assembly, parallel to the first rotation stopper pin, a hinge pin (9) and the rising stem, for im proving stability in the dise assembly and safeguarding against buckling and deformation of the dise assembly members due to forces applied from multiple directions.