1. Pengenalan
Swing check valve is a critical component in fluid control systems, engineered to automatically prevent backflow in pipelines.
Its core function is to ensure that fluid flows in only one direction, protecting pumps, pemampat, and other downstream equipment from potential damage caused by reverse flow.
These valves operate without external control or actuation, relying solely on flow dynamics and gravity to open and close the internal disc.
The widespread use of swing check valves spans numerous industries, including water and wastewater treatment, minyak dan gas, penjanaan kuasa, pemprosesan kimia, and fire protection systems.
Their mechanical simplicity, combined with excellent reliability and ease of maintenance, makes them a popular choice for both low- and high-pressure applications.
2. What is a Swing Check Valve?
A swing periksa injap is a type of injap bukan pulangan designed to allow fluid to flow freely in one direction while automatically preventing backflow.
The valve achieves this function through a simple mechanical design: a disc or flap (the “swing element”) is suspended on a hinge or shaft within the valve body.
When fluid flows in the intended direction, the force of the flow pushes the disc open.
If the flow reverses, the disc swings back into the closed position under gravity or reverse pressure, effectively sealing the passage and blocking backflow.

Kunci Komponen injap of a Swing Check Valve
| Komponen | Fungsi | Bahan biasa |
| Badan | Main pressure-retaining structure; connects to pipeline | Cast iron, besi mulur, keluli karbon, Keluli tahan karat, gangsa |
| Cakera (Flap) | Moves with flow direction; swings open to allow flow, closes to prevent backflow | Keluli tahan karat, gangsa, rubber-coated metal |
| Hinge & Pin | Enables disc to pivot smoothly and reliably | Keluli tahan karat, keluli aloi |
| Tempat duduk | Sealing surface that the disc rests against to block backflow | Metal-to-metal (machined), or soft seat (EPDM, Ptfe) |
| Bonnet (Cover) | Seals upper part of valve; allows access for maintenance | Same as body (Mis., besi mulur, keluli, gangsa) |
| Stop Pin / Bumper | Limits disc travel; Mengurangkan Slamming, bunyi bising, dan pakai (pilihan) | Stainless steel or other wear-resistant alloys |
3. How Swing Check Valves Work
Swing check valves operate using a graviti- or flow-actuated disc that swings open or closed within the valve body, depending on the direction of the fluid flow.
They are designed specifically to prevent reverse flow in pipelines, ensuring that media such as water, minyak, gas, or steam flows in only one direction.
Prinsip kerja
- Aliran ke hadapan (Valve Open):
When fluid flows in the intended direction, The momentum of the flow pushes the disc away from the valve seat.
The disc swings on a hinge or pivot mechanism, allowing fluid to pass through with minimal resistance. - Aliran terbalik (Valve Closed):
If the flow reverses or pressure drops downstream, gravity and/or back pressure forces the disc to swing back onto the seat, forming a seal that blocks backflow. - Closure Speed:
Critical to performance. Slow closure may allow backflow, while rapid closure can cause “water hammer”—a pressure surge from sudden fluid deceleration.
Spring-loaded designs or dashpots (fluid-filled dampers) mitigate this by controlling closure time (0.5-2 saat).
This action is fully automatic—no external operator or actuator is needed. The valve responds purely to changes in flow direction and pressure differential.
4. Common Types of Swing Check Valves
Standard Swing Check Valve
- Penerangan: A traditional design featuring a disc hinged at the top inside the valve body.
The disc swings open when fluid flows in the forward direction and closes under gravity or reverse flow pressure. - Kelebihan: Mudah, cost-effective design with robust construction; easy to maintain and suitable for horizontal installations.
- Aplikasi: Potable water systems, irrigation lines, Sistem HVAC, and general-purpose industrial pipelines.
Tilting Disc Swing Check Valve

- Penerangan: Uses a disc that tilts on a pivot shaft located slightly above its center, allowing partial opening with less pressure and smoother movement.
The design prevents full swinging, improving control. - Kelebihan: Quick closing, reduced water hammer, better suited for applications with fluctuating flow or low pressure differentials.
- Aplikasi: Sistem stim, process industries, penjanaan kuasa, and thermal fluid pipelines.
Dual Plate (Double Disc) Periksa injap

- Penerangan: Contains two spring-loaded semicircular plates that open inward to allow flow. The plates quickly return to closed position when flow reverses.
- Kelebihan: Compact and lightweight with minimal pressure drop; ideal for reducing water hammer in tight spaces.
- Aplikasi: Minyak & Talian paip gas, petrochemical plants, platform luar pesisir, and shipboard systems.
Wafer Swing Check Valve

- Penerangan: Designed with a slim, flat body that fits between two pipe flanges without the need for extended face-to-face dimensions.
Usually features a lightweight disc and short swing path. - Kelebihan: Saves space and weight, easy to install in existing flange systems, economical for large-volume use.
- Aplikasi: Compressed air lines, chilled water loops, building services, and packaged systems.
Silent (Non-Slam) Periksa injap
- Penerangan: Incorporates a spring-loaded mechanism that ensures the disc closes gradually and quietly before flow reversal can cause hammering.
The spring assists the disc closure regardless of installation orientation. - Kelebihan: Eliminates water hammer, reduces noise, and allows installation in vertical, horizontal, or inclined positions.
- Aplikasi: Booster pump systems, high-rise building plumbing, fire protection loops, and clean water supply.
Spring-Assisted Swing Check Valve

- Penerangan: A hybrid swing design with an internal torsion or compression spring that accelerates the closure of the disc when flow stops or reverses.
- Kelebihan: Faster shut-off to prevent backflow, suitable for applications with pulsating flow or vertical installations.
- Aplikasi: Firefighting systems, irrigation networks, vertical piping installations, and pumping stations.
Y-Type Swing Check Valve

- Penerangan: The valve body and hinge mechanism are arranged at a 45° angle (“Y” shape), minimizing disc travel distance and improving responsiveness.
Often used where compactness and faster closure are needed. - Kelebihan: Penurunan tekanan rendah, improved flow characteristics, fast response to flow reversal, and reduced mechanical wear.
- Aplikasi: Steam return lines, chemical and pharmaceutical plants, and high-temperature or aggressive media systems.
Top-Hinged or Counterweight Swing Check Valve

- Penerangan: Features a disc mounted on a top external hinge, sometimes equipped with a lever arm, counterweight, or dashpot for controlled closure. Allows for adjustable response timing and slam prevention.
- Kelebihan: Tunable disc behavior, reduced slamming forces, ideal for large-diameter or high-pressure pipelines.
- Aplikasi: Municipal water mains, wastewater treatment facilities, hydropower stations, and pump discharge lines.
5. Bahan: Matching the Fluid and Environment
Selecting the appropriate material is crucial for the reliability, Rintangan kakisan, and longevity of a swing check valve.
The choice of material should be carefully matched to the nature of the conveyed fluid, operating temperature, Penilaian Tekanan, corrosiveness, and the installation environment to ensure optimal valve performance and durability.
| Bahan | Compatible Fluids | Julat suhu | Pressure Rating | Aplikasi biasa |
| Besi tuang | Air, udara, mild chemicals | -10°C to 120°C | Hingga 16 bar (230 psi) | Sistem HVAC, air yang boleh diminum, irrigation |
| Besi mulur | Air, Air kumbahan, non-corrosive fluids | -20°C to 150°C | Hingga 25 bar (360 psi) | Municipal water, wastewater treatment |
| Keluli karbon | Minyak, gas, wap, udara | -29°C to 400°C | Hingga 100 bar (1450 psi) | Petrokimia, garisan wap, industrial process fluids |
| Keluli tahan karat (304/316) | Air laut, asid, Alkalis, food-grade fluids | -196°C to 400°C | Hingga 64 bar (930 psi) | Marin, kimia, Farmaseutikal, makanan & minuman |
| Gangsa / Tembaga | Air laut, air yang boleh diminum, udara | -20°C to 200°C | Hingga 25 bar (360 psi) | Marin, paip, fire protection |
| Keluli aloi (Cr-mo) | High-temperature steam, hydrocarbons | Up to 540°C | Hingga 100 bar (1450 psi) | Penjanaan kuasa, penapisan, high-temp industrial systems |
| Plastik (PVC, CPVC, Ms) | Acids, bases, air, bahan kimia yang menghakis (low pressure) | 0°C to 90°C (PVC), up to 120°C (CPVC) | Hingga 10 bar (145 psi) | Rawatan air, dos kimia, pertanian |
6. Advantages and Limitations
Kelebihan of Swing Check Valve:
- Simple Design and Operation: Swing check valves have a straightforward design with fewer moving parts, making them easy to operate and maintain.
- Penurunan tekanan rendah: Apabila dibuka sepenuhnya, the valve offers minimal resistance to fluid flow, resulting in low pressure loss.
- Bidirectional Flow Prevention: They effectively prevent backflow, protecting pumps, pemampat, and pipelines from damage.
- Wide Range of Sizes: Available in various sizes, suitable for both small-scale and large industrial applications.
- Versatile Applications: Compatible with a broad spectrum of fluids including water, wap, minyak, and gases.
Batasan of Swing Check Valve:
- Slow Closing Speed: The valve’s disc swings closed slowly, which can cause water hammer or surges in some systems.
- Requires Sufficient Flow Velocity: Needs adequate flow velocity to fully open and avoid partial closure or chatter.
- Not Suitable for High Pulsation Systems: Systems with rapid flow reversals or pulsations may reduce valve effectiveness and life span.
- Potential for Wear and Tear: The hinge mechanism and seating surfaces can wear over time, especially in abrasive or corrosive environments.
- Orientation Sensitivity: Proper installation orientation is critical; improper positioning can lead to malfunction or premature failure.
7. Common Applications of Swing Check Valve
- Rawatan air dan air sisa: Used to prevent backflow in pipelines carrying clean or treated water, sewage, and effluent.
- Pumping Systems: Installed on discharge lines of pumps to avoid reverse flow that could damage pump components.
- HVAC Systems: Applied in heating, pengudaraan, and air conditioning systems to maintain flow direction and prevent backflow.
- Industri minyak dan gas: Used in pipelines and processing units to safeguard against reverse flow of crude oil, refined products, and natural gas.
- Penjanaan kuasa: Commonly employed in steam and condensate lines to ensure unidirectional flow and protect turbines and boilers.
- Pemprosesan kimia: Suitable for fluids with moderate corrosiveness where flow direction control is critical.
- Sistem Perlindungan Kebakaran: Integrated into sprinkler systems to prevent water backflow, ensuring system readiness.
- Marin Aplikasi: Utilized in ballast and cooling water systems due to their reliability in preventing reverse flow under varying pressures.
8. Industry Standards and Compliance
Swing check valves are manufactured in accordance with:
- API 594 – Check Valve Design Standard
- ASME B16.34 – Pressure-temperature ratings
- ISO 5208 / API 598 – Pressure testing
- Dalam 12334 – European standard for check valves
- AWWA C508 – Valves for waterworks systems
9. Kesimpulan
Swing check valves play a vital role in fluid systems, offering a reliable, cost-effective solution to prevent reverse flow.
Their simple design, broad material options, and adaptability make them suitable across a range of industries—from clean water and sewage to oil & gas and power plants.
Proper valve selection, pemasangan, and maintenance are key to maximizing performance and longevity.
Ini: Penyelesaian pemutus injap ketepatan tinggi untuk menuntut aplikasi
Ini adalah penyedia perkhidmatan pemutus injap ketepatan yang khusus, Menyampaikan komponen berprestasi tinggi untuk industri yang memerlukan kebolehpercayaan, Integriti tekanan, dan ketepatan dimensi.
Dari casting mentah ke badan injap dan perhimpunan sepenuhnya machined, Ini Menawarkan penyelesaian akhir-ke-akhir yang direka untuk memenuhi piawaian global yang ketat.
Kepakaran pemutus injap kami merangkumi:
Pelaburan Pelaburan untuk badan injap & Potong
Menggunakan teknologi pemutus lilin yang hilang untuk menghasilkan geometri dalaman yang kompleks dan komponen injap toleransi ketat dengan kemasan permukaan yang luar biasa.
Pemutus pasir & Casting acuan shell
Sesuai untuk badan injap sederhana hingga besar, bebibir, dan bonet-menawarkan penyelesaian kos efektif untuk aplikasi perindustrian yang lasak, termasuk minyak & Penjanaan Gas dan Kuasa.
Pemesinan ketepatan untuk injap sesuai & Integriti meterai
CNC machining of seats, benang, dan wajah pengedap memastikan setiap bahagian cast memenuhi keperluan prestasi dimensi dan pengedap.
Julat Bahan untuk Aplikasi Kritikal
Dari keluli tahan karat (CF8/CF8M/CF3/CF3M), tembaga, besi mulur, kepada bahan dupleks dan aloi tinggi, Ini Bekalan Casting Injap yang Dibina Untuk Melakukan Dalam Kakisan, tekanan tinggi, atau persekitaran suhu tinggi.
Whether you require custom-engineered check valves, butterfly valves, Palam injap, Injap Globe, injap pintu, atau pengeluaran volum tinggi casting injap perindustrian, DEZE is your trusted partner untuk ketepatan, ketahanan, dan jaminan kualiti.
Soalan Lazim
When should I choose a swing check valve over a lift check valve?
Swing check valves are better for high-flow, low-pressure-drop applications (Mis., Air utama).
Lift check valves are preferred for small diameters or where tight shutoff at low pressures is critical (Mis., fuel lines).
How do I prevent water hammer in swing check valves?
Use spring-loaded designs, dashpots, or restrictors to slow closure. Sizing the valve for the system’s flow rate (avoiding oversizing) also reduces slamming.
Can swing check valves handle steam?
Ya, but use metal-seated valves (carbon steel or stainless steel) rated for high temperatures (up to 1200°F) and comply with ASME B16.34.
What is the lifespan of a swing check valve?
In clean water systems, bronze or stainless steel valves last 10–20 years. In abrasive or corrosive environments, lifespan may shorten to 3–5 years without maintenance.
Are swing check valves suitable for vertical pipes?
Standard designs are not, but spring-loaded swing check valves work in vertical lines, as the spring ensures the disc closes regardless of orientation.



