GB2584475A

GB2584475A - Nozzle check valve assembly

Info

Publication number: GB2584475A
Application number: GB1908031.6A
Authority: GB
Inventors: Whyte Philip; Lusty Simon; Moore Richard
Original assignee: Crane Chempharma and Energy Flow Solutions Germany
Current assignee: Crane Chempharma and Energy Flow Solutions Germany
Priority date: 2019-06-05
Filing date: 2019-06-05
Publication date: 2020-12-09
Anticipated expiration: 2039-06-05
Also published as: GB201908031D0; GB2584475B

Abstract

A nozzle check valve assembly comprises a valve body having a fluid inlet 111, a fluid outlet 112, and a fluid conduit therebetween, and an insert comprising a nozzle 131, a diffuser 141, and a sealing means 117, 151. The insert is reversibly connectable to the valve body and when connected, the diffuser is upstream of the nozzle 131 and downstream of the sealing means 117, 151. The sealing means is configured to move in an axial direction relative to the valve body to open and close the fluid conduit.

Description

Intellectual Property Office Application No. GII1908031.6 RTM Date:18 October 2019 The following terms are registered trade marks and should be read as such wherever they occur in this document: Inconel Intellectual Property Office is an operating name of the Patent Office www.gov.uk /ipo

NOZZLE CHECK VALVE ASSEMBLY

Field of the invention

This invention relates to nozzle check valves. In particular, though not exclusively, the invention relates to nozzle check valves used in corrosive environments such as in the transport of petroleum products; as well as kits and uses of the same.

Background of the invention

An important aspect of a check valve is to protect equipment and prevent damage caused by backflow.

Engineers often require valves to close quickly to prevent flow reversal that can damage mechanical equipment. Nozzle check valves are self-actuating non-return valves, designed to allow fluid flow in one direction, thereby protecting fluid pumping source equipment. An example of a check valve is shown in Figures 1 and 2. They are specifically designed for fast-reversing systems where backflow is a concern. Nozzle check valves minimize the damaging effects of water hammer in fluid systems; remove chattering associated with conventional valves; protect rotating equipment from damage due to flow reversal; minimize pressure loss in piping systems; and provide a quick dynamic response reducing any reverse velocity.

When nozzle check valves are used in corrosive environments, the exposed parts must be maintained regularly and/or must be protected from the corrosive environment. Protecting these parts is especially difficult due to the complex internal shapes and surfaces of the nozzle check valve with integral diffuser, if it can be done at all. This is particularly true of the nozzle, rib/web areas and the diffuser surfaces. Casting the whole valve out of a high-grade material is costly. In the alternative, the nozzle check valve can be regularly inspected and replaced, but this has the downside of having to shut down the pipeline, which can lead to a loss of productivity.

There remains a need in the art for improved solutions to the problem of maintaining pipe systems containing nozzle check valves used in the transport of corrosive fluids, such as petroleum products. They also find application in a wide range of fluid handling applications including water, chemical, pharmaceutical, food, desalination, nuclear, energy and oil refining.

Summary of the invention

In a first aspect of the invention, there is provided a nozzle check valve assembly comprising: a valve body comprising: a fluid inlet, a fluid outlet, and a fluid conduit therebetween; an insert comprising: a nozzle, a diffuser, and a sealing means wherein the insert is reversibly connectable to the valve body; and wherein, when connected: the diffuser is upstream of the nozzle and downstream of the sealing means, and wherein the sealing means is configured to move in an axial direction relative to the valve body to open and close the fluid conduit.

The present invention is in effect formed of a main body and an insert that goes into the main body.

This has two main advantages over the prior art nozzle check valve with the integral diffuser. Firstly, all the parts of the nozzle check valve of the invention are readily accessible (e.g. ribs, diffuser, etc). This means that these parts can be treated in any manner necessary, e.g. to be coated/clad in a corrosive resistant material.

Secondly, this allows the insert and valve body to be manufactured separately, and to different specifications. For example, the insert containing the more complex geometric surfaces (e.g. nozzle, webs, diffuser, etc.) can be cast as a single (monolithic) unit from a high-grade corrosive resistant material (e.g. a nickel-chromium alloy such as Inconel 625 alloy or Inconel 825 alloy). On the other hand, the valve body can be made of a lower grade material (e.g. carbon steel), and the 'wetted parts' (i.e. those in contact with the corrosive fluid) of the body could be coated/clad in a corrosive resistant material (e.g. weld clad in Inconel 625 alloy or Inconel 825 alloy). Since the valve body makes up the greater part of the mass of the valve assembly, this approach of cladding only the 'wetted surfaces' of the valve body can result in a considerable cost saving (and a consequential reduction in the use of rare elements). The cost of the raw materials used can be reduced by up to 30 to 60%. Since large nozzle check valves can be quite sizable (e.g. weighing up to or 10,000 kg), this saving in material costs is significant.

Further, since the valve body and insert can have different specifications, the cheapest method of manufacture can be used in each case. Indeed, cost savings can be made by using a modular manufacturing process, and/or tendering the work out to the most cost-effective manufacturing party.

Accordingly, the present invention provides all the benefits of a high-quality cast integral diffuser nozzle check valve of the prior art, but at a fraction of the price. It also offers the possibility of easier and cheaper maintenance solutions. For example, in a case of a fault, only the failed part (e.g. the valve body or the insert) needs to be replaced/repaired, as opposed to having to replace the whole casted unit. Indeed, in the case of the valve body, it could be simply re-clad.

In an embodiment, the surfaces in contact with the fluid (in use) are suitably protected from any adverse conditions. This may for example be a surface treatment, coating, or cladding. The invention offers the possibility that an appropriate protective material can be selected according to need. For example, in the food industry corrosive conditions are also experienced, but these may place different demands on the equipment as compared to in the petroleum industry.

In an embodiment, the assembly comprises cladded surfaces, wherein the cladded surfaces contact a fluid when the assembly is in use. In an embodiment, the assembly comprises cladded parts, wherein the cladded parts comprise surfaces in contact with the fluid, when the assembly is in use. In an embodiment, the cladded surfaces/parts are weld cladded. However, other possibilities exist, such as Fusion Bonded Epoxy lining, ebonite lining, or rubber lining. In an embodiment, the cladded surfaces/parts are inert. In an embodiment, the cladded surfaces/parts are inert to the conditions present when pumping sour crude oil under elevated/extreme temperature and/or pressure (e.g. 196°C to +550 °C and/or 200 psi to 10,000 psi). Again, these can be used in a wide range of fluid handling applications including water, chemical, pharmaceutical, food, desalination, aerospace, nuclear, energy, and oil refining.

In an embodiment, the cladded surfaces comprise surfaces defining the fluid conduit, and/or the nozzle and/or the diffuser. In an embodiment, the cladded surfaces comprise internal surfaces of the valve body. In an embodiment, the cladded parts comprise the nozzle and/or diffuser. In an embodiment, the cladded parts comprise the valve body.

In an embodiment, the cladding comprises a high alloy and/or steel such as Inconel 625 alloy (UNS N06625/W.Nr. 2.4856) or Inconel 825 alloy (UNS N08825/W.Nr. 2.4858). Inconel 625 alloy is a nickel-chromium alloy and is used for its high strength, excellent fabricability (including joining), and outstanding corrosion resistance. This alloy is particularly suitable for use within the petroleum industry.

ASTM (American Society for Testing and Materials) for various products made out of Inconel 625 are as follows: Wipe Sea B444 d Tu B444 tied Shee P 5704 5443 Bar In an embodiment, Inconel 625 alloy refers to the specification of the alloy as available on 1 January 2019.

In an embodiment, the protective alloy used in the cladding has a chemical composition falling within the below stated ranges:

M

Max 23 0.4 0.1 5 0.5 0.015 0.015

N

Balance Balance 4.15 3.15 0.4 Al 0.5 Si

M 1.5

51.0 50.5 20.5 50.35 475-5.5 50.006 00704 50.015 80.08 80.015 50.015 50.50 00.50 80.35 i 503 7-11 Renw3inder 20.8 x58.0 >53 20.0-23.0 55.0 7-11 8.0-10.0 3.15-4.15 01.0 00.5 50.50 20.50 5.0.4 00.4 00.5 14 0-17.0 1.0 2.25-2.76

N n 60.10 51.0

50.0-' 55.0 21.0 0.65--1.15 10.0--15.0 872.0 511.0 14 0-57.0 24.0 00.5 20.5 5.0-10.0 23.0 870.0 5.0-0.0 81.0 0 00.5 50.5 60.08 50.01 Alloys falling within the below chemical ranges are also considered: In an embodiment, the valve body is cast, forged or made from billets or bar. These methods are relatively cheap and convenient methods of manufacture. In an embodiment, the valve body comprises carbon steel or any other low alloy steel. Carbon steel is a strong and relatively inexpensive material. In an embodiment, the 'wetted areas/parts' of the carbon steel are clad. In an embodiment the insert, except the sealing means, is cast as one piece, and optionally comprises or consists of a nickel-chromium alloy (e.g. Inconel 625 alloy or Inconel 825 alloy) or high alloy materials. Optionally, in this embodiment, the insert is clad. This may be a viable option for large inserts. In an embodiment the cladding consists of a nickel-chromium alloy such as an Inconel 625 alloy or any suitable high alloy steel.

Due to the relatively complex geometry of the insert parts (e.g. the nozzle, ribs/webs and the diffuser), it is convenient to cast these insert parts together as an integrated unit, and attach the sealing means to it. While these could be clad in a corrosive resistant material, due to the complex geometry, it is beneficial to cast the insert as a single unit out of the corrosive resistant material.

In an embodiment, the protective alloy used in the insert has a chemical composition falling within the below stated ranges: CrMO CO Min 20 8 Max 23 10 1 0.5 0.015 0.015

N

Balance Balance 3.15 0.4 0.4 0.5 4.15 0.1 5

S

Alloys falling within the below chemical ranges are also considered.

In an embodiment, each of the nozzle, diffuser and sealing means are arranged centrally about the axial direction relative to the valve body, when the valve assembly is in the assembled state.

In an embodiment, the insert and valve body reversibly screw together. When the assembly is assembled, the insert reversibly connects to the valve body in a fluid tight manner. In an embodiment, the insert reversibly screws into the valve body. In an embodiment, the insert comprises a threaded portion, the threaded portion mating with a cooperating recess in the valve body. In an embodiment, the threaded portion comprises a locking threaded portion. In an embodiment, the locking threaded portion has a locking angle in the range 5 to 40 degrees, optionally a locking angle of 15 degrees. While it is possible to connect the insert and valve body together in a number of ways, it is convenient to screw the two parts together. A locking angle on the threaded parts helps to ensure that the two parts stay together when the valve is installed and used. It is also possible for the two parts, once connected, to be connected in an irreversible manner.

In an embodiment, the insert comprises a collar, the collar comprising the threaded portion. In an embodiment, the collar is connected to the nozzle and/or diffuser by a plurality of webs/ribs. The dimensions of the collar may closely match an internal bore of the valve body, to align and facilitate the screwing of the insert into the valve body, and to give a support structure from which the parts of the insert may depend.

In an embodiment, the insert is prevented from rotating relative to the valve body by anti-rotation fixing means. In an embodiment, the insert is reversibly fixed to the valve body by one or more grub screws. In an embodiment, the collar is reversibly fixed to the valve body by one or more grub screws. Once the assembly is assembled, and in particular when in use, it is important that the valve assembly holds together. This can be done by for example making holes in the collar of the insert and inserting grub screws, the grub screws fitting into recesses/holes in the valve body. This in effect tacking the two parts together, and so acts to prevent the two parts coming apart by rotating relative to each other. Relative rotation of the insert to the valve body might otherwise occur due to 1.5 51.0 1 50.5 50.5 1.0 2.75 00.4 50.4 51.0 3.15-4.15 50.50 1 00.50 50.35 1 503 475-5.5 50.006 7-11 Renv3inder 50.35 00.04 50.015 50.08 50.015 1 50.015 14 0-

ITO 24.0

6.0-10.0 23.0 10.0--15.0 50.8 672.0 --* 61.0 14 0-17.0 2.25- 50.08 1 53.01 1

N 00.5 60.5 8.0-10.0 20.0-23.0 55.0 7-11 658.0 >58 60.5 00.5

50.50 50.50 00.-10 51.0 0.65--1.15 50.0 55.0 * ,,, *. ,, , 21.0 670.0 5.0-0.0 51.0 51.0 00.5 60.5 any vibration experienced during use. Other fixing means that achieve the same goal are also considered (e.g. using a retaining ring).

In an embodiment, the insert is prevented from moving in an axial direction relative to the valve body by anti-separation means. In an embodiment, the valve body comprises a recess, the recess located downstream of the insert, and wherein the recess is capable of reversibly receiving a fixing ring or projecting part. The fixing ring or projecting part preventing the insert moving in the downstream direction. Separation of the insert and valve body might otherwise occur due to any vibration experienced during use. Other fixing means that achieve the same goal are also considered. It is also possible to attach the output end of the assembled valve assembly to a downstream pipe which has a bore too narrow to allow the insert to travel down it. The down stream bore is narrower than the insert/collar.

In an embodiment, the sealing means comprises an obturator. In an embodiment, the sealing means comprises a plate. Hereafter references to 'plate' also encompass 'obturator'. In an embodiment, the plate is substantially circular and/or domed/plug shaped. A sealing means in the form of a circular plate is a convenient shape for sealing a bore-like fluid conduit. For example, the conduit is sealed when the sealing means is pushed up against a narrowing in the valve body (valve seat), usually a constriction in the bore-like conduit. Other shapes of sealing plate are also considered, so long as they act in the necessary fashion.

There are several ways to attach the sealing means to the rest of the insert. In an embodiment, the nozzle comprises a central barrel, the central barrel extending axially through the diffuser, the barrel extending in the upstream direction. In an embodiment, the sealing means comprises an axial extension configured to pass into/through the central barrel. In an alternative embodiment, the nozzle is equipped with the axial extension and the sealing means is equipped with the central barrel (i.e. the reverse of the above). In an embodiment, the sealing means further comprises a guide bush, the bush provided around the axial extension between the axial extension and the central barrel. In an embodiment, the sealing means further comprises a spacer, the spacer provided around the axial extension, between the axial extension and the central barrel. In an embodiment, the diffuser is attached/fixed to the central barrel of the nozzle.

In an embodiment, a resilient means is located between the sealing means and the diffuser, wherein the resilient means is in a compressed state when the fluid conduit is open. In an embodiment, a spring is arranged between the sealing means and the diffuser. In an embodiment, the spring is in a compressed state when the fluid conduit is open. A helical spring is a convenient way to spring bias the valve sealing means to the closed position. Other resilient means are considered.

In an embodiment, the sealing means abuts against the diffuser when the fluid conduit is fully open. The upstream end of the diffuser can mate neatly with the downstream end of the sealing means, forming a low drag surface. This allows the fluid to pass around the diffuser and aiding the fluid to achieve a venturi effect conserving energy across the embodiment.

In an embodiment, the sealing means opens under a pressure of at least 0.1 psi, and optionally at least 5.0 psi. In an embodiment, the assembled assembly is operable under a pressure of up to 20,000 psi, optionally between 200 and 15,000 psi; and further optionally between 500 and 10,000 psi. When the pressure of the fluid acting on the sealing means is sufficient, it will act against the spring opening the fluid conduit. When it is fully open, the sealing means may abut the upstream surface of the diffuser. When the pressure drops, the sealing means returns to the close position sealing the conduit. The diffuser acting to prevent the liquid slamming backwards against the sealing means.

In an embodiment, the assembly meets industry standards ASME B16.34, API 6D and/or the Pressure Equipment Directive 2014/68/EU, wherein the standards are those in force on 1 January 2019.

In an embodiment, the valve body has flanged ends. In an embodiment, the inlet and outlet areas of the valve body are flanged (e.g. flanged inlet and outlet plates). The flanged ends may be equipped with holes to allow a fixing bolt to pass through. In an embodiment, the valve body comprises a lifting handle or lifting loop. The valve assembly may be bulky and/or heavy, and so having carrying handles and/or a loop to accept a hook can be useful. In an embodiment, the fluid conduit comprises a fluid bore from 0.5 to 100 inches, and optionally 2 to 84 inches. Connections such as butt welded ends, bolted flanges and hub clamp connections can be accommodated in the embodiments. The valve internal parts will follow naturally from the same principle right through the sizes.

In a second aspect of the invention, there is provided the use of a nozzle check valve assembly as defined in the first aspect. In an embodiment, the nozzle check valve assembly is used in the petroleum industry.

In a third aspect of the invention, there is provided a nozzle check valve assembly kit comprising: a valve body and an insert as defined in the first aspect.

In a fourth aspect of the invention, there is provided a system comprising the valve assembly of the first aspect. In an embodiment, the system is a pipe system, for example in water, chemical, pharmaceutical, food, desalination, aerospace, nuclear, energy, and oil refining industries.

It is also considered that the insert (with or without the sealing means) as defined in the first aspect could be provided. Supply of the insert alone (with or without the sealing means), for example as a replacement part, is considered; and as such the valve body may not be required in all cases.

The present invention will now be further described with reference to the following non-limiting examples and the accompanying illustrative drawings, of which:

Brief description of the drawings

Figure 1 is a perspective view of a nozzle check valve with integral diffuser of the prior art.

Figure 2 is a cross-section view of the one-piece nozzle check valve in Fig. 1.

Figure 3 is an exploded perspective view of an embodiment of the invention.

Figure 4 is a perspective view of an embodiment of the invention.

Figure 5 is a cross-section view of an embodiment of the invention.

Figure 6 is a perspective cross-section view of the outlet end of an embodiment of the invention.

Figure 7 is a cross-section view of the outlet end of an embodiment of the invention. Figure 8 is a perspective view of the insert of the invention.

Like features have been given like reference numerals.

Detailed description of the invention

Figure 1 shows a nozzle check valve of the prior art (10), being cast as a single piece. The one-piece nozzle check valve with integral diffuser has a fluid inlet (11) and a fluid outlet (12) and a fluid conduit therebetween. It has flanged inlet and outlet ends (13 and 14). The flanged ends have holes (15) which allow it to be bolted into position in a pipe system. The centrally disposed nozzle (16) is substantially cone shaped, widening in the upstream direction, and connects to the walls of the fluid conduit by three ribs/webs (17).

Figure 2 is a cross-section view of the embodiment in Fig. 1., which in addition shows a centrally dispose diffuser (18), extending from the nozzle, and is cone-like, widening in the upstream direction. The nozzle comprises a central bore (19), the central bore opening axially into the centre of the diffuser. A sealing plate (not shown) comprises an axial extension (not shown) passing through the central bore. A spring (not shown) positioned around the axial extension pushes the plate to engage with the valve seat (20), closing the fluid conduit. Under sufficient pressure, the sealing plate will move axially in the downstream direction opening the conduit.

Figure 3 is an exploded perspective view of an embodiment of the invention (100).

The valve body (110) has a fluid inlet (111) and a fluid outlet (112), and a fluid conduit therebetween. The valve body has flanged inlet end (113) and outlet end (114). The flanged ends have holes (115), which allow it to be bolted into position in a pipe system. The valve body has lifting rings (116) which allow it to be lifted by heavy machinery. The valve body is cast from carbon steel and the parts that will be in contact with the fluid in use (e.g. the central bore) are weld clad in Inconel 625 alloy.

The nozzle unit (130) and diffuser unit (140) of the insert (120) are cast as a single piece from Inconel 625 alloy. The centrally disposed nozzle (131) has a circular cross section and widens in the upstream direction. The nozzle connects via three ribs/webs (132) to a collar (133). The collar has downstream threaded parts (134) and upstream threaded parts (135). The downstream threaded parts reversibly mate with a cooperating recess in the valve body. The upstream threaded parts (135) have a 15 degree locking angle, which mates with a cooperating recess in the valve body. This helps to lock the insert to the valve body. Three grub screws (136) screws through holes (137) in the collar and fit into recesses/holes in the valve body.

The nozzle comprises a central barrel (138), the central barrel extending axially through the diffuser unit (140), the barrel extending in the upstream direction. The diffuser (141) has a circular cross section and widens in the upstream direction.

The sealing means unit (150) has a circular domed sealing plate (151), which together with sealing seat (117) closes the fluid conduit, when the sealing plate contacts the sealing seat. The sealing plate is equipped with an axial extension (152) configured to pass through the central barrel (138). Around the axial extension, is a (downstream) guide bush (153), a spacer (154), (an upstream) guide bush (153) and a sealing ring (155). A helical compression spring (156) is mounted on the end of the central barrel, and is compressed when the sealing plate (151) moves in a downstream direction.

Figures 4 to 6 show the same embodiment (100), or parts of the same embodiment, as shown in Figure 3. Like parts are given like numerals. Figure 4 is a perspective view of an embodiment of the invention; Figure 5 is a cross-section view of an embodiment of the invention; Figure 6 is a perspective cross-section view of the outlet end of an embodiment of the invention.

Figure 7 is a cross-section view of the outlet end of an alternative embodiment of the invention (101). In this case the valve body comprises a recess (118), the recess located downstream of the insert, and wherein the recess is capable of reversibly receiving a fixing ring (119), the fixing ring preventing the insert moving in the downstream direction. In this embodiment the insert is fully within the valve body.

Figure 8 is a perspective view of the insert (150) as shown in Figures 1 to 7.

Claims

Claims 1. A nozzle check valve assembly comprising: a valve body comprising: a fluid inlet, a fluid outlet, and a fluid conduit therebetween; an insert comprising: a nozzle, a diffuser, and a sealing means; wherein the insert is reversibly connectable to the valve body; and wherein, when connected: the diffuser is upstream of the nozzle and downstream of the sealing means, and wherein the sealing means is configured to move in an axial direction relative to the valve body to open and close the fluid conduit.
2. An assembly according to claim 1, comprising cladded surfaces, wherein the cladded surfaces contact a fluid when the assembly is in use.
3. An assembly according to claim 1 or 2, wherein the cladding comprises nickel-chromium alloy or a high steel alloy, optionally the alloy is Inconel 625 alloy or Inconel 825 alloy.
4. An assembly according to any one of the preceding claims, wherein the valve body is cast, forged, or made from billets or bar.
5. An assembly according to any one of the preceding claims, wherein the insert, excepting the sealing means, is cast as one piece, and optionally comprises a nickel-chromium alloy or high steel alloy; further optionally the alloy is Inconel 625 alloy or Inconel 825 alloy.
6. An assembly according to any one of the preceding claims, wherein the insert and valve body reversibly screw together.
7. An assembly according to any one of the preceding claims, wherein the insert reversibly screws into the valve body.
8. An assembly according to any one of the preceding claims, wherein the insert comprises a threaded portion, the threaded portion mating with a cooperating recess in the valve body.
9. An assembly according to any one of the preceding claims, wherein the insert comprises a threaded portion, the threaded portion mating with a cooperating recess in the valve body, and wherein the threaded portion comprises a locking threaded portion.
10. An assembly according to claim 8 or 9, wherein the insert comprises a collar, the collar comprising the threaded portion.
11. An assembly according to claim 10, wherein the collar is connected to the nozzle and/or diffuser by a plurality of webs/ribs.
12. An assembly according to any one of the preceding claims, wherein the insert is prevented from rotating relative to the valve body by anti-rotation fixing means.
13. An assembly according to any one of the preceding claims, wherein the insert is reversibly fixed to the valve body by one or more grub screws.
14. An assembly according to any one of the preceding claims, wherein the insert is prevented from moving in an axial direction relative to the valve body by anti-separation means.
15. An assembly according to any one of the preceding claims, wherein the valve body comprises a recess, the recess located downstream of the insert, and wherein the recess is capable of reversibly receiving a fixing ring or projecting part, the fixing ring or projecting part preventing the insert moving in the downstream direction.
16. An assembly according to any one of the preceding claims, wherein the sealing means is a plate.
17. An assembly according to any one of the preceding claims, comprising a spring arranged between the sealing means and the diffuser.
18. An assembly according to claim 17, wherein the spring is in a compressed state when the fluid conduit is open.
19. An assembly according to any one of the preceding claims, wherein the sealing means abuts against the diffuser when the fluid conduit is fully open.
20. An assembly according to any one of the preceding claims, wherein the sealing means opens under a pressure of at least 0.1 psi, and optionally at least 5.0 psi.
21. An assembly according to any one of the preceding claims, wherein the assembly is operable under a pressure of up to 20,000 psi, and optionally between 200 psi and 15,000 psi.
22. Use of a nozzle check valve assembly as defined in any one of the preceding claims; optionally in the pumping of petrochemical products.
23. A nozzle check valve assembly kit comprising: a valve body and an insert as defined in any one of the preceding claims.
24. A system comprising the valve assembly of any one of claims 1 to 21.
25. A nozzle check valve assembly substantially as herein described with reference to or as illustrated in the accompanying drawings.