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Having 26 series -312 varieties - over 1000 pump models
Focused on water pump research and development manufacturing for 36 years
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Packing gland
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Genuine accessories
Horizontal Single-Stage Fire Pump
Accessory Details
Structural features and technical requirements for packing gland:
The packing gland is primarily used to compress the packing material, ensuring a tight seal between the packing and the valve stem, while also providing support for the valve stem. From a structural perspective, the packing gland is a sleeve with a diamond-shaped flange at one end; it is classified as a sleeve-type part and thus shares the typical characteristics of such components. The main surfaces of the packing gland are the inner and outer cylindrical surfaces, which have strict requirements for coaxiality. The end of the packing gland is typically machined into an internal conical surface with an angle of approximately 150°.
Depending on the valve’s specific application—such as stainless steel ball valves, WCB hard-sealed ball valves, or cast iron soft-sealed ball valves—the packing materials can be carbon steel, stainless steel, cast iron, or non-ferrous metals. The raw blanks are primarily castings and forgings. For large- and medium-scale production, the steel packing gland can be manufactured using precision casting to produce the raw blank; in this case, with the exception of the inner and outer cylindrical surfaces and the inner conical surface, no machining is required for any other parts.
The main technical requirements for the packing gland are as follows:
1. The dimensional accuracy of the inner bore is H11 grade, the dimensional accuracy of the outer cylindrical surface is d11 grade, and the surface roughness is Ra 6.3 to 3.2 μm.
2. The inner bore and the outer cylinder have high requirements for coaxiality.
The machining process of the packing gland:
The inner bore and outer diameter of the packing gland are both machined by turning. To ensure the required coaxiality, the inner bore, outer diameter, and end face should all be machined in a single setup. Since installation errors no longer affect machining accuracy, this machining method can achieve very high positional accuracy between parts.
Machining of internal holes and external circles
To ensure the required precision in mutual positioning, the inner bore and outer diameter of the packing gland cover should be turned in a single setup. However, one end of the gland cover features a diamond-shaped flange, which cannot be clamped on a three-jaw chuck. If a four-jaw chuck is used instead, alignment would be necessary, resulting in low efficiency. Typically, a two-jaw automatic centering chuck is employed to clamp the packing gland cover. This type of fixture is easy to use, guarantees machining quality, and has good versatility. When machining packing gland covers of different sizes, all that’s needed is to replace the V-shaped jaws.
When machining cast iron packing gland covers, multi-blade tools can be used. This composite flat drill, made of high-speed steel, enables the simultaneous machining of the workpiece’s internal bore and end conical surface on a conventional lathe, resulting in high efficiency.
Why choose us?
Changsha Zhonghlian Pump Industry Co., Ltd. was founded in 1989 and was independently established after the restructuring of Changsha Water Pump Factory. It is a comprehensive national high-tech enterprise integrating design, research and development, manufacturing, and service. The company was listed on the Hunan Provincial Equity Exchange on December 31, 2019, with the abbreviation "Zhonghlian Pump Industry" and the equity code: 600275HN. It is currently a key backbone enterprise in China's centrifugal pump industry and one of the major professional manufacturers of multi-stage pumps in the country. The headquarters is located in Changsha City, Hunan Province, a historical and cultural city in China.
Square meters of land area
100% factory pass rate
Square meters of land area
100% factory pass rate
Q
What is your typical delivery time?
A
Models in stock can be shipped the next day at the latest. All others are custom-made, with lead times generally ranging from 7 to 90 days depending on the product size and project specifics. Please contact our sales manager for details: 0731-88632200 。
Q
Do you have centrifugal pumps in stock?
A
Centrifugal pumps come in numerous models and configurations. Except for a small number of high-volume, standard models that are in stock, the vast majority are not stocked and are customized products. We need to select a pump based on your site's flow rate, head, media temperature, pH value, and installation conditions, etc., to determine the pump model and configuration before we can submit an order to the factory for production.
Q
What information should I provide when requesting a quote?
A
Generally, to obtain an accurate quotation, we recommend providing us with the following information: pump flow rate, head, on-site operating voltage and frequency, temperature, pH value, and solid particle content of the fluid being conveyed, and on-site installation conditions (horizontal or vertical installation), etc.
If you are not sure, don't worry, our business managers will assist you in determining this.
Q
What products do you mainly produce?
A
Zhonglian Pump Industry manufactures various large industrial centrifugal pumps. Main products include: self-balancing multi-stage pumps, multi-stage centrifugal pumps, single-stage centrifugal pumps, split-case pumps, chemical pumps, submersible pumps, pipeline pumps, long-shaft pumps, condensate pumps, etc.
Q
Why is it so slow to get a price quote?
A
Because centrifugal pumps are non-standard customized products with many models, the price range is also very large. Even for the same model, the price difference is also very large due to different materials and configurations. Taking the most common water pump accessory—the impeller—as an example, the price of a stainless steel impeller is several times that of a cast iron impeller. Therefore, we need to clarify the relevant information to give you an accurate price. Normally, if you provide relatively comprehensive information, we can quote within 5 minutes.
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Hotline:
+86 0731-88632200
Export Trade/Technical Support:
+86 153-4831-2290
Head Office Email:
zoomlian@yeah.net
No. 210, Huanbao Zhong Road, Yuhua District, Changsha City, Hunan Province, Leowoju Wisdom Valley Building B, 8th Floor
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