Two-Piece Steel Ball Valve

1. What is the difference between 1-piece, 2-piece, and 3-piece ball valves?

The 1-piece ball valve body has an integral structure with no obvious detachable parts. It features a compact structure, low cost, and convenient installation. However, it needs to be completely removed for disassembly and maintenance, and is suitable for small-diameter and low-pressure pipelines.

The 2-piece ball valve consists of a valve body and two parts of the valve cover, which are connected by threads or flanges, ensuring structural stability and facilitating certain maintenance convenience. The valve cover can be removed separately to replace internal seals and other accessories. It is suitable for multiple medium and low-pressure fluid scenarios. It is a commonly used type for civil and small commercial use.

The 3-piece ball valve body is composed of three parts: the left valve body, the right valve body, and the middle valve seat, which are connected by bolts. It is not necessary to dismantle the connection between the whole valve and pipeline during disassembly and maintenance. It can be directly opened to access the middle part, allowing for the replacement of core parts, such as the valve core and valve seat.

From DuraChoice

2. What are the advantages of two-piece ball valves over other valves?

One-piece ball valves have a fully closed, single-piece body. The ball and seat are pushed into the valve through a necking process. This design is compact and low-cost, but the inner diameter is usually smaller than the pipe. It creates pressure loss and reduces flow efficiency. If the seat or seal wears out, you can’t repair it. You have to cut the whole valve out and replace it, which raises maintenance costs.

Three-piece ball valves have two end caps and a separate middle body. The middle section can be taken off the line. The structure is more complex, and the cost is much higher than two-piece valves. It has two sealing surfaces, so there’s one more possible leak point than two-piece valves. It also needs stricter installation and maintenance.

Two-piece ball valves are made of a main body and one end cover. The structure is simple, with a good balance of performance.

Standard two-piece ball valves are full-bore. When open, the inner channel matches the pipe size. Fluid flows smoothly, with almost no pressure loss. It works for most industrial and civil systems, with a simple design and a better price.
It only has one connection point. Possible external leak points are half those of three-piece valves, so it’s more reliable long-term.

The two-piece structure gives customers real performance and stability at a better price. You don’t pay extra for unnecessary repair features. This directly improves project profit margins.

3. What pressure testing standards do you follow for the 2-piece ball valve?

Plumberstar two-piece ball valve pressure tests are conducted strictly in accordance with API 598. We test key items like shell strength and sealing performance. This makes sure that delivered products are safe and reliable.

• To check the valve shell is strong enough, we do this:Put the valve in a half-open position. Inject water pressure inside. The pressure is at least 1.5 times the valve’s maximum rated working pressure. Under this high pressure, we check closely for leaks where the valve body and cover connect. We make sure there’s no rupture or external leakage.
• To test the valve’s sealing performance: Fully close the valve seat from one end. Check if the other end leaks. Then apply pressure from the opposite end. Repeat the test. This ensures perfect two-way sealing.
• For special uses or high-demand custom orders, we also do air pressure tests. Air molecules are much smaller than water molecules. This test can find tiny leaks that water pressure tests can’t detect.

What’s more, Plumberstar can provide a pressure test report for every batch of your order.

4. Can you provide MTRs for two-piece ball valve raw materials?

Plumberstar two-piece ball valves come with a complete, standard raw material MTR (Material Test Report). All materials are from qualified, long-term cooperative steel mills. Each batch of steel has an original material report when entering the factory. After warehousing, it is linked to the production batch in the system. This ensures the material source is clear, the data is real, and batches can be traced.

On this basis, we can provide original material confirmation certificates. They are based on material heat numbers and test data, and match product batch numbers and order numbers one by one. These certificates can be shipped with the goods and used for project acceptance and filing.

For projects needing higher certification, we can help arrange third-party testing, such as SGS, BV, TÜV, and Intertek. They do spectral material analysis and issue independent reports, improving project compliance and international recognition.

All pressure-bearing and core parts are under material traceability management. Each MTR has a unique heat number and production batch number. This forms a fully traceable system from raw materials to finished products.

Before shipment, we can provide a PDF electronic MTR in advance for your inspection, customs clearance, or filing. Original paper certificates are included in the goods. Each batch and order includes complete, standard documents.

5. Can two-piece ball valves provide different handle options?

Plumberstar two-piece ball valves offer flexible handle configurations. You can choose different handle styles, structures, materials, and operation methods. Just pick based on your installation space, usage frequency, operating habits, appearance needs, and export standards.

All handles are designed and made to our factory’s structural standards. They have enough strength, lock reliably, and open/close smoothly. They won’t affect the valve’s sealing or pressure resistance.

• An in-line (straight) handle is the most common standard type. It opens and closes quickly at 90°, with a simple structure and easy operation. It works for most pipeline systems, small equipment, and regular engineering projects.
• Curved/Butterfly handle has a bigger grip area. It feels more comfortable to use and won’t slip easily. It’s good for frequent opening/closing, and for humid or oily environments.
• The extended handle provides more operating torque. It’s suitable for large-diameter or high-pressure valves. It also works well when the valve is installed deep or has limited operating space, making it easier to use.
• The foldable handle can be folded and stored. It saves installation space and prevents collision damage. It’s ideal for tight areas—like inside cabinets, equipment cavities, or narrow pipe wells.
• Lockable handle lets you add a padlock. This stops wrong operation or unauthorized opening/closing. It’s used in places with high safety needs, such as engine rooms, fire protection systems, and industrial pipelines.

We also support brand customization for handles. You can emboss logos on metal handles or silk-screen them on plastic-dipped sleeves. Logos are clear, durable, and won’t fall off. All customization is part of our standard production process. It won’t delay delivery or affect bulk supply stability.

6. How long is the warranty period for two-piece steel ball valves?

Two-piece steel ball valve custom models or products that reach a specific pressure level can be guaranteed for a period of 2 years.

Other models that meet CE, ISO, and other high standards, as well as those used for special conditions or products with long-term cooperation orders in large quantities, may have a warranty period of up to 3 years.

High-end models with special actuators even come with a 5-year special actuator warranty. The specific duration will usually be further defined in the trade contract in conjunction with the customer’s needs.

7. Are your two-piece ball valves manufactured in your factory?

Yes, the body and bonnet are manufactured in our own factory. Our manufacturer also produces Stem and PTFE(Teflon). But the Level handle/butterfly handle and ball are sourced from outside partners.