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SiChuan Liangchuan Mechanical Equipment Co.,Ltd Company Profile

Factory Tour
Production Line

Valve Production Process Valve body
Valve body (casting, surfacing welding)
Procurement of castings (according to standard)-In-plant inspection (according to standard)-Surfacing tank
——Ultrasonic flaw detection (according to the drawing) —Surface welding and post-weld heat treatment—Finished machining—Grinding sealing surface—Seal surface hardness inspection, color inspection. Valve Trim Manufacturing Process

A . Internal parts that need to be welded sealing surface, such as valve disc, valve seat, etc.
Raw material procurement (according to the standard)-factory inspection (according to the standard)-production of blanks (round steel or forgings, according to the drawing process requirements)-rough machining ultrasonic flaw detection surface (when the drawing requires)-rough machining surfacing tank- —Surface welding and post-weld heat treatment—finishing various parts—grinding sealing surfaces—seal surface hardness testing, color inspection.


B . valve stem
Raw material procurement (according to standards)-In-factory inspection (according to standards)-Production of blanks (round steel or forgings, according to the drawing process requirements)-Rough machining surfacing tank-Surfacing and post-weld heat treatment-Finishing various departments — Grinding the outer circle — Surface treatment of the valve stem (nitriding, quenching, chemical plating) — Final treatment (polishing, grinding, etc.) — Grinding the sealing surface — Sealing surface hardness inspection, color inspection.


C . No internal welding surface
Raw material procurement (according to the standard)-factory inspection (according to the standard)-production of blanks (round steel or forgings, according to the drawing process requirements)-rough machining of ultrasonic flaw detection surfaces (when the drawings require)-finishing of various parts Fasteners

Fastener manufacturing standard DL439-1991.
Raw material procurement (according to the standard)-factory inspection (according to the standard)-making blanks (round steel or forgings, according to the drawing process requirements) and sampling for necessary inspection-roughing-finishing-spectral inspection Final assembly
Obtaining parts-cleaning, cleaning-rough assembly (according to the drawing)-hydrostatic test (according to drawings, processes)-after passing, dismantling, cleaning-final assembly-debugging with electrical equipment or actuators ( For electric valves)-paint packaging-shipping.


I . OEM cooperation methods:

1. OEM processing, 2 . Sample processing, 3 . New product development, 4 . Customized design


Suitable for: international and domestic dealers with their own brands or investors with many years of industry experience.



II . ODM cooperation methods:


One-stop service for brand processing, providing trademark registration, product architecture combination, packaging design, and accessories selection


Suitable for: The company develops new brands, and agents or distributors produce their own brands.



OEM / ODM service object:


A . Valve professional line sales customers;
B . Various valve export trade customers;
C . Semi-finished products processing services of the same valve factory;
D . Agents and distributors who are interested in creating their own brand;



Service positioning:


Because each customer's requirements (material, nameplate, color, size) of the finished product are different, the specific quotation is based on the actual sample product. Our company has all kinds of valve products (customers can provide drawings, tailored for you)






1. Quality control of raw materials

Raw materials are the source of product quality assurance. They must be purchased from qualified suppliers and must be controlled. Quality of raw materials


Quantity control should include: appearance, identification, size, re-testing of physical and chemical composition, NDT, quantity and related heat treatment information (graph, record, report), material certificate, certificate of conformity, etc.
The raw materials are qualified, and protective measures are taken to prevent rust and bumps. They should be put into storage or put into use according to the prescribed procedures and keep relevant records.
If the inspection of raw materials is unqualified, a non-conformity review and disposal list shall be issued in accordance with regulations, timely communication and coordination shall be made to close the problem.


2. Machining quality inspection


Mechanical processing is a processing technology that removes materials through mechanical precision processing.This process is an important step to achieve the final product.
one. The machining equipment and the skill level of the personnel used in the machining process have an important effect on the machining accuracy of the parts (three dimensions, position, shape) and production efficiency, so the effective quality control of the key processes in the machining process .


The quality control of machining process should strictly observe the following regulations:
1) Review the rationality of the processing technology.
2) Check the relevant processing instructions according to the production schedule.
3) The manufacturer shall complete the product self-inspection and make relevant key size records.
4) The supplier inspector shall conduct inspections and completion inspections, and make corresponding process inspection records.
5) If the processed product involves a welding procedure, it shall be operated in accordance with the welding procedure specification and relevant records shall be made.
6) After the machining is completed, the parts should be properly marked (order information, material furnace number, specifications, qualified or unqualified, etc.), put in the corresponding position, and take protective measures.


3. Assembly inspection


Assembly is to assemble the parts according to the specified technical requirements to prepare for subsequent debugging. For assembly
For inspection, the following points should be noticed:


1) Review the assembly drawing and assembly process
2) Check process card and picking list
3) Check the surface quality of the parts with assembly, remove foreign matter, rust spots, burrs and other foreign objects
4) Material identification check of assembly parts
5) Appearance, identification (including serial number), size inspection and related identification of the first assembled finished product, and make records.


4. Stress test


Pressure test is an important means for functional testing of valves, which ensures that product performance meets standard requirements and meets


Customer requirements. Stress testing shall adopt applicable standards in accordance with the technical agreement or contract. Before testing the valve, make sure that the body is clean and tidy, free of foreign matter, and must not be painted.


1) The sampling rate of the pressure test is 10% of each item, at least 2; if the test finds a leak, 20% of the remaining quantity is randomly selected for testing; if the leak is still found, all inspections are performed.

2) After the pressure test of the valve is finished, the water surface and other impurities should be cleaned. Carbon steel valves should be well protected against rust.

3) Make stress test records

4) For details, please refer to the "Guide to Pressure Testing of Valves"

5) Torque test must be performed for polished rod valves to ensure that the torque meets the standard requirements.

6) If other special test tests are involved, such as fire test, high / low temperature pressure test and micro-leak test, it is necessary to strictly implement the relevant inspection standards and make good records.


5 . Inspection of valve products


After the valve is pressure tested, it indicates that the valve has met the basic performance requirements.
Various tests have ended. After it has been inspected for the final appearance size, it is ready to be transferred to the next step.


1) Identification inspection
Body identification: LOGO, specification level, pressure level, material number, furnace number, flow direction mark
Note: Flow direction signs are mainly for one-way sealed valves, such as globe valves, check valves, butterfly valves, cryogenic ball valves, etc .; for DBB


The structure of the ball valve requires a two-way flow direction mark.
Cover (or connection bracket) identification: material number, furnace number (you can use no pressure / specification identification, if there is, make sure


Ensure accuracy and clarity)
Internal parts identification: metal internal parts must have material number and furnace number identification. Non-metallic materials are not required


Nameplate: Detailed manufacturer, product and standard information. If the nameplate does not have a serial number, the body should have a serial number.


2) Visual inspection
Appearance of casting: It should meet the requirements of MSS SP 55, and the surface rust-proof grade reaches sa2.5 level 2.

Appearance of forgings: no obvious defects such as cracks, repair welding, corrosion, burrs, etc.


3) Dimension inspection
According to the drawings or standard requirements, check the structural size of the finished valve and make corresponding size records.


6 . Paint inspection
Paint plays an important role in protecting and aesthetics of the valve surface quality. The quality of the paint is important to the life of the valve.
One of the indicators. Paint inspection usually includes: surface roughness of the body, dry film thickness of paint, paint color, paint surface quality and paint adhesion. Specifically, the "Paint Process Specifications" should be strictly implemented. Relevant inspection records should be made after each inspection.


7 . Packaging inspection
Before packaging: The valve surface should be kept clean and tidy. Carbon steel flange sealing surface, the welding end should be coated with butter / varnish, etc.
To prevent rust. The channel should be sprayed with rust preventive oil to prevent rust. The joint should be sealed with a plastic cover to avoid injury during transportation.
When packing: a single valve should be packed in a separate bubble bag. The inside of the box should be primed with plastic cloth or linoleum. valve
Place them in order. The valves should be separated by paper plates, etc., and the layers should be separated by thin wooden boards to prevent collision during transportation.
Parts / accessories should be individually packaged and secured.
According to the agreement, do you need to attach the warranty documents and related materials with the box.
There should be a detailed packing list on the outside of the wooden box and corresponding directions, moisture, and drop resistance signs


8 . Data review
When the valve is shipped, relevant quality technical documents, reports and records should be provided according to the requirements of the technical agreement and contract.
It is used to ensure that the product meets the relevant standard requirements. A data collection checklist should be prepared to ensure the integrity of the data and not to omit it.

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