GB2520576A

GB2520576A - Method for manufacturing control valve components

Info

Publication number: GB2520576A
Application number: GB1320864.0A
Authority: GB
Inventors: Scott Crawford
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-11-26
Filing date: 2013-11-26
Publication date: 2015-05-27
Also published as: GB201320864D0

Abstract

The method for manufacturing a valve or valve trim (Figure 3) uses additive manufacturing techniques. The valve or valve trim includes one or more tortuous flow paths 3. An alternative method of manufacturing is for a sacrificial element or mould for a valve or valve trim having one or more tortuous flow paths. The additive manufacturing technique may be 3D printing.

Description

This invention relates to a method or process for manufacturing control valve components.

Previously, high pressure or severe service control valves have been created by manufacturing and combining multiple discs which have been individually machined or cast. The resulting plates are then bonded or bolted together to form a completed valve trim, which is subsequently installed within a valve body.

Examples of such valves include but are not limited to those described by:-EP1746320 B1 -Fluid trim apparatus and method US 2008021032 Al -Control Valve with Vortex Chambers US 8474484 B2 -Fluid control US 2009021799 Al -Fluid Control US 7320340 B2 -Fluid pressure reduction devices US 3722854 A -Valve with perforated ribbon silencing element US 3921668 A -High energy loss rolled strip fluid control device The nature and shape of the flow path through the cage body (a typical format of which is shown in item 3 of Figure 2) previously prevented these parts from being cast as a single part or machined or drilled from a solid block.

The stacked arrangement (shown by figure 3) requires significant time to manufacture, and also results in an increased potential for leakage due to the sealing requirements between each plate.

These problems can be overcome by using additive manufacturing techniques such as:- * 3D printing * Fused deposition Modelling * Electron Beam Freeform Fabrication * Direct Metal Laser Sintering, * Electron Beam Melting, * selective Laser Melting, * Selective Laser Sintering, * Selective Heat Sintering, * Plaster based 3D printing * Laminated Object Manufacturing,

Description -1

* Stereo lithography) * Digital Light Processing, * Metal clay printing * Other additive techniques with the exception of casting These techniques are described by a number of existing patents which include but are not limited to: -US5204055 -Three-dimensional printing process to fabricate moulds and prototypes involving selectively applying binder to successively deposited powder layers.

U54863538 -Apparatus. for production of parts by selective sintering comprising a laser beam controllably directed onto a layer of powder.

US5387380 -Producing component by selectively bonding powder in deposited layers by applying bonding liquid employing 3-dimensional printing technique, based on ink jet printing and building up successive layers.

U56259962 -Three dimensional printing system for computer aided design models, cures 3D models build up in layers by dispersing photopolymer material, using UV or IRradiation optionally.

US 944817 -Formation of multilayer parts by sintering comprises depositing layers of powder mixt.

materials and scanning each individual layer with a sintering radiation beam.

By utilising such additive type processes, the trims or cage can be manufactured as a single complete component while maintaining a torturous flow path. This will significantly reduce the number of steps involved in the process and therefor, the cost of and time taken to manufacture the trim. In addition, the single piece design will also reduce the leakage rate across the resulting valve as no leak paths exist between sections.

Figures The method will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a typical layout of a blank layer where the black areas represent the material deposited by the chosen additive process.

Figure 2 shows a typical layout of a labyrinth layer where the black areas are the new material deposited by the chosen additive manufacturing technique and the white areas represent areas where no material is deposited.

Description -2

Figure 3 shows a typical configuration of the final labyrinth arrangement and depicts the build-up of the cage using alternating layers of blank plate layers and labyrinth layers as shown in figure land 2 respectively.

Figure 4 shows typical steps currently used in the manufacturing process of a stacked valve trim.

FigureS shows the steps required to produce a valve trim using an additive manufacturing process.

Example

A labyrinth design is first created to suit the required process conditions, calculated volume and pressure drop requirements of the application.

The resulting design will typically comprise of a number of alternating discs as shown in FigureS, where the design of each disc is similar (but not identical) to those shown in Figures land 2.

The design of the flowpath on the discs (see item 3 of Figure 2) may differ from layer to layer to give the required flow characteristics across the full valve range.

A coniputerised 3D model of the resulting design is then created and computer software used to slice the final 3D shape into 2D layers, similar to those shown in Figures 2 and 3.

A 3D printer is then used to recreate the final 3D form, by depositing multiple layers on top of each other. For example, first, many copies of a layer (as shown in figure 2) will be printed on top of each other.

Next a number of layers of the type shown in figure 2 will be printed. The number and style will differ between applications.

This process of printing layers is repeated until the required number of alternating discs has been created and the full height of the trim is achieved.

The final trim can then be removed, post treated if necessary, before being installed within the valve body.

A similar process can be used where prior to slicing in software, the trim is inserted into a 3D model of the valve body and the entire body and trim sliced and then printed as a single component.

Similarly, should the process conditions require a higher strength material than can be achieved with the materials used in additive manufacturing processes, a sacrificial element can be produced using additive manufacturing. The resulting part can then be used in a sacrificial process similar to wax loss to create the final element.

Description -3

Claims

Claims 1. A method for manufacturing a valve or valve trim featuring one or more torturous flowpaths utilising additive manufacturing techniques.
2. A method of manufacturing a sacrificial element or mould for a valve of valve trim featuring one or more torturous flowpaths.