A Fluid End and Method of Manufacturing IT

Abstract

The present invention discloses a Fluid End and its manufacturing method. The conventional fluid end manufacturing methods involve machining of all surfaces.

This demands more input stock for manufacturing process and a lot of material wastage during machining process. In the conventional processes involving open die forging followed by machining result into only about 34% utilization of material. In the present invention, fluid end component geometry is optimized. Assembly surfaces are machined whereas other or non-assembly surfaces are as-forged condition. The method of invention also results in significant reduction in machining time and chip removal. The present invention also discloses a process of manufacturing using a combination of open die and closed die forging, and machining. It involves the steps of cogging an ingot to form billet for closed die forging using open die forging, forging the billet in closed die using forging equipment, semi-finish/rough/partial machining, heat treatment, drilling and finish machining the component. Most of the non-assembly areas of the fluid end are left in as-forged condition.

Claims

1. A fluid end (1) comprising a main block (2), a flange (3), said main block (2) and flange (3) connected by a neck (4) wherein said fluid end (1) has a first and a second surface (and 8), said first surface (7) being the surface of said main block (2) nearer the flange (3) and said second surface (8) being the surface of said main block (2) away from said flange (3), and wherein said fluid end (1) has a number of assembly (5) and non-assembly surfaces (6), characterised in that assembly surfaces (5) are finished by machining and at least some of non-assembly surfaces (6) are left in as-forged condition as indicated in FIGS. 5, 6, 7, and 8.

2. A method of manufacturing a fluid end characterised in that said process comprises the steps of a. forging of an ingot into a billet using open die method; b. forging said billet by providing blows in multiple steps to achieve near net shaped fluid end; c. rough machining outer surfaces of assembly areas of the said near net shaped fluid end and keeping non-assembly surfaces as forged to achieve rough machined near net shaped fluid end; d. providing heat treatment to said rough machined near net shaped fluid end to achieve a heat treated rough machined near net shaped fluid end; e. providing further semi-finish or partial or rough machining to the said heat treated rough machined near net shaped fluid end; f. drilling for creating internal pathways; g. providing finish machining to produce fluid end.

3. A method as claimed in claim 2 characterised in that said multiple steps of providing blows further comprise the steps of: a. heating said billet to forging temperature and providing a first set of blows to produce a first-heated finisher; b. if required, heating the first-heated finisher further and providing a second set of blows by placing said first-heated finisher in a closed die to produce a second-heated finisher; wherein either said first-heated finisher, or in the case said step b is executed, said second-heated finisher produces a near-net shape fluid end, ready to be machined.

4. A method as claimed in claim 3 characterised in that said closed die is constructed so that the material in the flange area of the forged product flows so as to provide continuous grain flow lines along the contours of fluid end.

Description

BRIEF DESCRIPTION OF DRAWINGS:

[0018] FIGS. 1 and 2 show perspective views of a fluid end manufactured using conventional process.

[0019] FIGS. 3 and 4 show side views of fluid ends manufactured using conventional process

[0020] FIGS. 5 and 6 show perspective views fluid ends manufactured using the process of invention

[0021] FIGS. 7 and 8 show side views of the fluid ends manufactured using the process of invention

[0022] FIG. 9 shows a flow-chart of the conventional manufacturing process for a fluid end

[0023] FIG. 10 shows a flow-chart of the method of manufacturing for a fluid end according to the invention

[0024] FIG. 11 shows the grain flow lines for the contour of the fluid end of the invention

[0025] FIG. 12 shows the die set up used in the manufacture of the fluid end according to the invention

[0026] (Please note that the as-forged areas of the invention are indicated by hatch markings.)

TABLE-US-00001 List of parts: 1. Fluid end 2. Main block 3. Flange 4. Neck 5. Assembly areas or surfaces 6. Non-assembly areas or surfaces 7. First surface 8. Second surface 9. Internal pathway 10. Protruded area 11. Die horn 12. Top die 13. Bottom die

SUMMARY OF THE INVENTION:

[0027] The present invention describes the innovated design of Fluid End and its innovated manufacturing method.

[0028] In the present invention, fluid end (1) component geometry is optimized in such a way that, assembly areas or surfaces (5) are kept in machined condition whereas other or non-assembly areas (6) or surfaces are kept in as-forged condition, as shown in FIGS. 5, 6, 7 and 8. With this inventive design, the input weight is reduced. Also this innovated design of Fluid End resulted into significant reduction in machining time and chip removal.

[0029] The present invention also discloses a process of manufacturing safety and application critical components using a combination of open die and closed die forging, and machining. The process involves the steps of cogging of the ingot to form billet for closed die forging using open die forging, forging the billet in closed die using forging equipment, semi-finish/rough/partial machining, heat treatment, drilling and finish machining the component. Most of the non-assembly areas (i.e. the surfaces where no mating part is being assembled) of the fluid end are left in as-forged condition (i.e. machining operation at such areas is eliminated).

[0030] With the process of the present invention, 70 to 75% of the shape and size of the final component is achieved through forging and remaining 25 to 30% through machining.

[0031] The Fluid End (1) with continuous grain flow lines along the contours, (see FIG. 11) and improved mechanical and metallurgical properties is obtained by this innovative design and innovative manufacturing method.

DETAILED DESCRIPTION OF INVENTION:

[0032] The present invention is applicable to any forged components that are used in variety of industries, particularly those which are formed from large ingots. The invention is particularly useful for safety and application critical components such as fluid end (1) which is used in oil and gas industry. The description that follows is based on a typical such fluid end.

[0033] FIGS. 1 and 2 shows the perspective views of existing design of Fluid End. FIGS. 3 and 4 show some of the side views of the products shown in FIGS. 1 and 2. It is evident from FIGS. 1, 2, 3 and 4 that all the assembly faces and non-assembly faces of conventional Fluid End are machined. Most of the outer surfaces of the Fluid End's existing design are non-assembly surfaces. Hence there is wastage of material and machining time on non-assembly surfaces.

[0034] FIGS. 5 and 6 show perspective views of innovative design of the fluid end (1) and FIGS. 7 and 8 show some of the side views of the products shown in FIGS. 5 and 6, respectively.

[0035] As seen from FIG. 5, the fluid end (1) of the invention has a main block (2) and a flange (3). The area between the flange (3) and the main block (2) is a neck (4). The face of the main body facing the flange is termed first surface (7). The first surface (7) is interrupted by the neck (4). The face of the main block away from the flange is termed as the second surface (8). The second surface (8) is interrupted by a protruded area (10) that runs across the length of the fluid end (1). As seen from FIGS., 5, 6, 7, 8 The first surface (7) and the second surface (8) both comprise as-forged (6) and machined (5) areas or surfaces. The proportion of the as-forged areas or surfaces (6) as a percentage of the total surface area of the second surface (8) is substantial.

[0036] The fluid end (1) has a number of internal pathways (9) for fluid movement. In one embodiment of the invention, the pathways are formed as inter-connected holes provided within the body of the main block, the flange, and the neck.

[0037] The innovative design of fluid end (1) of the invention consists of machined (5) as well as as-forged surfaces (6). The assembly surfaces are machined while most of the non-assembly surfaces are formed as-forged. Here most of non-assembly surfaces are kept as-forged which means no machining is required on these surfaces. As shown in FIGS. 5 and 6, the first surface (7) has at least one non-assembly surface that is kept in as-forged condition. The non-assembly surfaces of the first surface (7) are provided between the fluid-carrying holes. The areas of the non-assembly surfaces, where machining is carried out are the areas where lifting holes may be provided.

[0038] The conventional manufacturing process as shown in FIG. 9, involves following steps, [0039] open die forging of ingot to rectangular blank, [0040] rough machining, [0041] heat treatment, [0042] partial machining, [0043] finish machining

[0044] The conventional manufacturing process leads to a lot of wastage of material and energy.

[0045] On the other hand, the process of the present invention as shown in FIG. 10, involves the following stages: [0046] a. forging of an ingot into a billet using open die method; [0047] b. forging in a closed die the said billet by providing blows in multiple steps to achieve near net shaped fluid end; [0048] c rough machining outer surfaces of assembly areas of the said near net shaped fluid end and keeping non-assembly surfaces as forged to achieve rough machined near net shaped fluid end; [0049] d. providing heat treatment to said rough machined near net shaped fluid end to achieve the heat treated, rough machined, near net shaped fluid end; [0050] e. providing further semi-finish or partial or rough machining to the said heat treated rough machined near net shaped fluid end, while leaving most of the non-assembly areas in as-forged condition; [0051] f. drilling for creating internal pathways, once again, leaving most of the non-assembly areas in as-forged condition; [0052] g. providing finish machining to produce fluid end.

[0053] It can thus be understood that the areas that are formed by forging technique and left as as-forged during the partial/rough/finish machining stages are left as as- forged in the final product.

[0054] As shown in FIG. 10, in the open die forging the cogging of the ingot produces a billet for the closed die forging. In the closed die forging, the billet is placed in between top and bottom dies and blows are given by hammer. This closed die forging is carried out in multiple steps. In the first step the billet is heated to forging temperature and a first set of blows are given depending on the part geometry and die closure dimension. A first-heated finisher results as a result of the first set of blows. After providing the required number of blows, if required, the product is further heated and then placed in the closed dies for the second set of blows. This helps to produce a second-heated finisher which is the near-net shaped component which is then subjected to machining. In the instance where the first set of blows is sufficient, the first-heated finisher results in the near-net shaped fluid end.

[0055] The neck (4) portion between the flange (3) and the main block (2) of the fluid-end (1) is difficult to forge integrally with the rest of the fluid end (1). This portion can be seen clearly in FIGS. 7 and 8 (and also partly in FIGS. 5 and 6). The process of the invention includes a step of designing the forging dies in such a way that the material will flows in the flange area to provide continuous grain flow lines (see FIG. 11).

[0056] With an iterative simulation approach, numerous manufacturing concepts for forging and machining were evaluated to optimize part geometry of near net shape, forging die design and manufacturing process using virtual manufacturing techniques. Forging part geometry i.e. near net shape and process was optimized using 3D metal flow simulation and machining process was optimized using CAM simulation. Based on simulation results, an optimal manufacturing methodology was developed for manufacturing components such as the fluid ends used in the oil and gas industry.

[0057] FIG. 12 shows the top and bottom dies (12 and 13) used in closed die forging of fluid end, separated by parting line (PL). The figure also shows the die horns (11), which are an integral part of both the dies. Provision of adequately designed die horns helps to create flange (3) of the main body with deeper cavities on both sides of fluid end for the formation of neck (4). However, this leads to frequent yielding/deformation/deflection of the die horns. Also the flange is difficult to fill up in the conventional methods, since ratio of cavity depth to width is high. The die horn design of the method of invention (optimisation and simulation as explained above) is such that it overcomes these drawbacks.

[0058] The Fluid End with continuous grain flow lines along the contours was achieved by adding closed die forging stage in between open die forging and machining process.

[0059] The near net shaped component (the fluid end) is next partial machined to remove the draft on forged fluid end (1). This step is then followed by heat treatment to achieve the required metallurgical and mechanical properties. After this, holes are drilled for creating internal pathways as per the component specification followed by finish machining to achieve the final shape and size.

Operational Benefits:

[0060] A number of operational benefits have been observed as a result of the present invention. These have been summarised here: [0061] 1. Reduction in input weight for forging. [0062] 2. Significant reduction in machining time

[0063] 3. Productivity improved.

[0064] It is evident from the foregoing discussion that the present invention has a number of embodiments.

[0065] 1. A fluid end comprising a main block, a flange, said main block and flange connected by a neck wherein said fluid end has a first and a second surface, said first surface being the surface of said main block nearer the flange and said second surface being the surface of said main block away from said flange, and wherein said fluid end has a number of assembly and non-assembly surfaces, characterised in that assembly surfaces are machined condition and at least some of non-assembly surfaces are in as-forged condition, as indicated in FIGS. 5, 6, 7, and 8.

[0066] 2. A method of manufacturing a fluid end characterised in that said process comprises the steps of: [0067] a. forging of an ingot into a billet using open die method; [0068] b. forging said billet by providing blows in multiple steps to achieve near net shaped fluid end; [0069] c. rough machining outer surfaces of assembly areas of said near net shaped fluid end and keeping non-assembly surfaces as forged to achieve rough machined near net shaped fluid end; [0070] d. providing heat treatment to said rough machined near net shaped fluid end to achieve the heat treated rough machined near net shaped fluid end; [0071] e. providing further semi-finish or partial or rough machining to the said heat treated rough machined near net shaped fluid end; [0072] f. drilling for creating internal pathways; [0073] g. providing finish machining to produce fluid end.

[0074] 3. A method as disclosed in embodiment 2 characterised in that said multiple steps of providing blows further comprise the steps of: [0075] a. heating said billet to forging temperature and providing a first set of blows to produce a first-heated finisher; [0076] b. if required, heating the first-heated finisher further and providing a second set of blows by placing said first-heated finisher in a closed die to produce a second-heated finisher; [0077] wherein either said first-heated finisher, or in the case said step b is executed, said second-heated finisher produces a near-net shape fluid end, ready to be machined.

[0078] 4. A method as disclosed in embodiments 2 or 3, characterised in that said closed die is constructed so that the material in the flange area of the forged product flows so as to provide continuous grain flow lines along the contours of fluid end.

[0079] While the above description contains much specificity, these should not be construed as limitation in the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. It must be realized that modifications and variations are possible based on the disclosure given above without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.