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Sponge connection on a pump

October 29, 2025
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A simple screw pump, also known as a progressive cavity pump, is a positive displacement pump used to pump viscous liquids, substances containing solid particles, and pastes. These pumps are widely used in industries such as oil and gas, food processing, refining, chemicals, and mining. The type of pump connection to the pipeline is fundamental to the installation and operation of a simple screw pump.   Flange connections
are      among the most common and reliable connection methods for this type of pump. They not only simplify installation and maintenance but also ensure system integrity.

The concept of lip contact

A flanged connection consists of two round metal plates fastened with bolts and nuts.   A gasket  between the plates prevents fluid from leaking. On pumps, flanges are typically installed at the inlet (suction port) and outlet (pressure port) and connected to the pipeline.

The use of flanged connections allows the pump to be connected to the circuit without cutting or welding pipes. This feature is very helpful during maintenance.

Types of cable ties

Flanges are classified according to the type of connection to pipes and the type of contact surface.

1. Lip types, classified according to the type of connection

  1. Weld-on flange:
    The pointed neck is welded to the pipe. This type of flange is suitable for high-pressure and high-temperature applications and is characterized by high mechanical strength.

  2. Mounting flange:
    The pipe is inserted through the flange and welded to the outside. This type of flange is easy to install but has low tensile strength.

  3. Weld socket flange:
    The pipe is inserted into the flange cavity and welded on the outside. Suitable for small-diameter pipes and medium pressure applications.

  4. Threaded flange:
    The pipe and flange are connected by a thread, eliminating the need for welding. This type of connection is  frequently   used in low-pressure and temporary systems.

  5. Blind lip:
    This type of lip is a plate-shaped lip without a central hole,  used to close the end of a pipe or pump opening.

  6. Ring flange:
    Used in systems with very high pressure and very high temperature. A metal ring, which acts as an insulator, is located between the two ends of the flange.

2. Type of lip surface

  1. Flat:
    The entire edge surface is in contact with the seal, suitable for low-pressure systems.

  2. Raised sealing surface:
    Part of the lip surface is slightly raised to     improve contact with the seal. This design is frequently used in pump construction.

  3. Two lips:
    One lip has a raised edge, the other a groove that holds the seal in place, thus ensuring a more precise seal.

  4. Ring connector:
    features a round groove for receiving a metallic sealing ring and is designed for high pressures.

Flanges are also     classified according to their pressure rating (e.g., Class 150, Class 300, Class 600, etc.). The choice of pressure rating should be based on the operating pressure of the system.

Advantages of using a flange connection for a single pump

  1. Easy opening and closing:
    For maintenance or component replacement, simply loosen the flange bolts to disconnect the pump from the system. No cutting or welding required.

  2. Reliable sealing:
    By using suitable seals, fluid leaks at the connection points can be prevented and system safety improved.

  3. High strength and durability:
    The flange withstands the high pressure and mechanical vibrations of the pump.

  4. Standardization option:
    Flanges are manufactured according to international standards such as ANSI, DIN or BS and are easily  compatible with other devices.

  5. Precise and safe installation:
    After proper installation, the flange connection can withstand axial and lateral loads, thus stabilizing pump performance.

Sibex Group D

Important points for the selection and installation of flange fittings

1. Select suitable materials.

The choice of sealing material depends on the type of medium and the operating conditions. In corrosive environments, stainless steel or special alloys are typically used, while carbon steel is sufficient for normal operating conditions.
Sealing materials must also possess the required resistance to heat, pressure, and abrasion. Common materials include rubber, polytetrafluoroethylene (PTFE), graphite, and pressed fibers.

2. Determine the nominal pressure.

The selected flange must withstand the system ‘s operating pressure . Using a flange with a lower pressure resistance can lead to leaks or breakage.

3. Precise alignment

The edges must be precisely aligned. Even a slight misalignment can lead to uneven   screw tension    and uneven pressure on the seal, which can ultimately result in leaks.

4. Tightening torque of the screws

The screws must be tightened crosswise to the specified torque to ensure even pressure distribution across the seal. Overtightening or undertightening can damage the seal.

5. Correct pipe mounting

Pipes attached to the edges must be supported by brackets and bases to prevent the weight or vibrations of the pipes from being transferred to the edges.

6. Regular review

Over time, the mounting screws can loosen due to vibrations and temperature fluctuations. Regular checks and tightening of the screws prevent leaks.

Phases of the installation of a flange connection of a pump

  1. Check plans and standards:
    Before installation, ensure that the rim type    and size    meet the required project standards.

  2. Surface cleaning:
    The contact surfaces between the rim and the seal must be absolutely clean and smooth. Rust or dirt can lead to leaks.

  3. Lip liner placement: The lip liner should be positioned exactly in  the middle  of the lips
    and should not have any wrinkles or creases.

  4. Attach screws:
    Manually attach screws to align the edges.

  5. Tighten screws gradually:
    Tighten the screws in several steps in a crisscross pattern, applying a specific tightening torque to distribute the pressure evenly on the connection.

  6. Leakage test:
    After installation, the system must undergo a pressure test to ensure complete leak tightness.

Tips for using a pump

  • The inlet and outlet of a single pump are usually fitted with flanges to facilitate connection to pipelines.

  • When transporting viscous or corrosive liquids, corrosion- and abrasion-resistant edges and seals must be used.

  • When planning the installation location of the pump, sufficient space must be provided to loosen the screws and the separating flange.

  • Vibrations caused by the rotation of the pump impeller can lead to excessive stress on the rim edge, therefore precise alignment of the pump and piping is essential.

  • The tightening torque of the screws should be checked again both during initial commissioning and after several hours of operation, and adjusted if necessary.

Finally

Flange fittings are     essential components     of every pump system and play a crucial role in its safe and leak-free operation. Selecting the appropriate flange type, adhering to installation guidelines, and using high-quality materials increase the system’s durability and efficiency.
Flange fittings not only simplify pump assembly and disassembly but also reduce long-term maintenance costs. Strict adherence to technical standards and principles during the selection and installation of flange fittings ensures stable and reliable pump operation under all conditions.