FAQs of Coupling

1. What is the primary function of coupling in the valve system?

Coupling is a mechanical component connecting two shafts. Its core function is to transmit torque, compensate for shaft installation deviation, buffer vibration, protect the valve and driving equipment, and ensure stable and reliable valve opening and closing action.

2. What is the difference between “rigid” and “flexible” coupling?

A rigid coupling has a simple design and can transfer strong torque, making it good for precise valve shaft alignment. A flexible coupling has elastic parts that can correct misalignment, reduce vibrations, and work well for motor-driven systems. When the pipeline vibrates, flexible couplings are usually the best choice for valve systems.

3. What parameters do I need to provide when customizing the coupling?

Customers need to provide four main details:

1. Type, shaft diameter, and keyway size of the shaft to connect.

2. Valve working torque, valve model, or the driving power—we can also give suggestions.

3. Working environment, like temperature, type of fluid, vibration, or corrosion.

4. Installation space, including limits on length and diameter.

Our engineers will use these details to choose and calculate the right coupling, making sure it fits and works properly.

4. What is the significance of the “compensation amount” parameter of the coupling?

Compensation means how much the coupling shaft can safely move or shift.

For example, if the pipeline settles or the support bracket moves during valve installation, the shafts may not line up perfectly. In that case, it is recommended to select a flexible coupling with a compensation amount ≥0.3mm to avoid clamping or damage caused by a rigid connection.

5. What materials are mainly used for plumberstar couplings?

Primarily composed of brass, carbon steel, and stainless steel materials. Brass has medium corrosion resistance and good conductivity, making it suitable for HVAC and low-pressure gas valves. Carbon steel is low-cost, high-strength, suitable for ordinary water, air, and other non-corrosive conditions. Stainless steel acid and alkali resistance, seawater corrosion resistance, suitable for chemical engineering, marine engineering, and food-grade valves.

6. What is the degree of protection of the coupling?

The normal protection level of the product is IP54, which means it keeps out dust and resists water splashes. If the area has heavy rain or spray, you can choose IP65 products. This is done by adding a sealed end cap and a waterproof ring at the connection point. If the place has dust or oil, you can add a special protective cover to make the product last longer.

7. Is it challenging to install the coupling?

Low installation difficulty, conventional models do not require special tools, and ordinary technicians can operate them. Installation steps are simple: ① Clean the end faces of the two shafts to ensure no oil stains and impurities;② Insert the coupling into the two shafts respectively, align the keyway, and fix the set screws;③ Check the concentricity;④ Lock the connecting bolts. Installation instructions with schematics are provided, and video instructions are available for complex models.

8. What problems can occur if the coaxiality deviation of the two shafts of the coupling is too large?

Excessive deviation will lead to increased vibration and noise of the coupling. Long-term use will wear down the bearing, shorten its lifespan, and may cause shaft fracture in severe cases. The radial height can be adjusted by increasing or decreasing the valve support spacer or by moving the actuator position to change the axial alignment. If the deviation is large, a flexible coupling with a larger compensation amount can be selected.

9. Does Plumberstar support OEM/ODM cooperation for the coupling?

We support OEM and ODM cooperation. For OEM, we can print customer logos and make custom packaging. For ODM, our engineers can take your ideas, design, and develop the coupling, make prototypes, and produce in batches. We provide a full service from design to delivery. A confidentiality agreement is signed first to protect your ideas and rights.

10. What standards are used for coupling packaging?

Plumberstar is packaged individually in PE bags with foam cushioning. Multiple products are packed into corrugated boxes filled with bubble wrap. The entire structure is reinforced with plywood pallets and wrapped with stretch film to prevent moisture loss and enhance resistance. Conform to sea and air packaging standards. Each shipment passed the drop test.