Product Description
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Marine Check Valve - Definition & Function
A marine check valve (or non-return valve) is a specialized one-way valve designed for shipboard piping systems to prevent backflow of liquids or gases (e.g., seawater, fuel, oil, or compressed air). It ensures fluid flows only in the intended direction, automatically closing when flow reverses-critical for safety and system integrity in marine environment.
Key Features of Marine Check Valves
Automatic Operation
Opens when forward pressure exceeds the cracking pressure.
Closes instantly if backflow or pressure loss occurs (e.g., pump failure).
Robust Marine-Grade Materials
Bronze, stainless steel, or duplex alloys for corrosion resistance in seawater.
Reinforced elastomers for sealing in oily or chemical-laden fluids.
Types Used on Ships
Swing Check Valve: Hinged disc swings open/closed (common in large pipes).
Lift Check Valve: Disc moves vertically (high-pressure systems).
Ball Check Valve: Uses a floating ball (compact, for viscous fluids).
Dual-Plate Check Valve: Spring-loaded plates for rapid closure (reduces water hammer).
Critical Marine Applications
Bilge & Ballast Systems: Prevents flooding back into pumps.
Fuel/Oil Transfer Lines: Stops contamination from reverse flow.
Cooling Water Circuits: Protects engines/heat exchangers.
Firefighting Systems: Maintains pressurized water supply.
Why Ships Rely on Check Valves
- Safety: Avoids backflow-induced equipment damage (e.g., flooded bilges, pump cavitation).
- Maintenance Reduction: No manual intervention needed-works passively.
- Compliance: Meets IMO (International Maritime Organization) and class society (e.g., ABS, DNV) standards.
Check Valve vs. Other Marine Valves
| Valve Type |
Primary Function |
Marine Use Case |
| Check Valve |
Block reverse flow |
Bilge pumps, fuel lines |
| Globe Valve |
Throttle/adjust flow |
Cooling water control |
| Gate Valve |
Fully open/close flow |
Main seawater intake |
| Ball Valve |
Quick on/off operation |
Fuel tank isolation |
Need help selecting a check valve for a specific ship system? Ask away!
| Rating |
SIZE |
φd |
L |
H |
FF Flange |
| φD |
φC |
t |
| 5K |
50A |
50 |
190 |
97 |
130 |
105 |
16 |
| 65A |
65 |
220 |
119 |
155 |
130 |
18 |
| 80A |
80 |
250 |
129 |
180 |
145 |
18 |
| 100A |
100 |
280 |
146 |
200 |
165 |
20 |
| 125A |
125 |
330 |
171 |
235 |
200 |
20 |
| 150A |
150 |
380 |
198 |
265 |
230 |
22 |
| 200A |
200 |
460 |
235 |
320 |
280 |
24 |
| 250A |
250 |
550 |
290 |
385 |
345 |
26 |
| 10K |
50A |
50 |
210 |
109 |
155 |
120 |
20 |
| 65A |
65 |
240 |
126 |
175 |
140 |
22 |
| 80A |
80 |
270 |
136 |
185 |
150 |
22 |
| 100A |
100 |
300 |
153 |
210 |
175 |
24 |
| 125A |
125 |
350 |
180 |
250 |
210 |
24 |
| 150A |
150 |
400 |
205 |
280 |
240 |
26 |
| 200A |
200 |
480 |
242 |
330 |
290 |
26 |
| NO. |
Parts |
Material |
| 1 |
Body |
FC200 |
| 2 |
Bonnet |
FC200 |
| 3 |
Disc |
CAC406(BC6) |
| 4 |
Valve seat |
CAC406(BC6) |
| 5 |
Arm |
CAC406(BC6) |
| 6 |
Hinge pin |
C3604 |
| 7 |
Plug |
C3604 |
| 8 |
Hex. nut |
C3604 |
| 9 |
Washer |
C2801 |
| 10 |
Split pin |
C2600 |
| 11 |
Stud bolt |
SS400 |
| 12 |
Hex. nut |
SS400 |
| 13 |
Gasket |
NON ASBESTOS |
| 14 |
Gasket |
PTFE |
| TING |
FLUID CONDITION |
TEST PRESSURE(MPal |
| OIL AND PULSATION WATER |
NON-SHOCK WATER UP TO 120 |
HYDROSTATIC PRESS TEST(SHELL) |
HYDROSTATIC PRESS TEST(SEAT) |
| (SHELL) |
| JIS 5K |
0.5 |
0.7 |
1.05 |
0.77 |
| JIS 10K |
1 |
1.4 |
2.1 |
1.54 |
| RATING |
Nominal dia |
0d |
0D |
0C |
t |
L |
H |
WEIGHT [kg] |
| JIS 5K |
50A |
50 |
130 |
105 |
16 |
190 |
97 |
9.06 |
| 65A |
65 |
155 |
130 |
18 |
220 |
119 |
13.9 |
| 80A |
80 |
180 |
145 |
18 |
250 |
129 |
19.1 |
| 100A |
100 |
200 |
165 |
20 |
280 |
146 |
27.1 |
| 125A |
125 |
235 |
200 |
20 |
330 |
171 |
39 |
| 150A |
150 |
265 |
230 |
22 |
380 |
198 |
53.7 |
| 200A |
200 |
320 |
280 |
24 |
460 |
235 |
94.4 |
| 250A |
250 |
385 |
345 |
26 |
550 |
290 |
150 |
| JIS10K |
50A |
50 |
155 |
120 |
20 |
210 |
109 |
13.6 |
| 65A |
65 |
175 |
140 |
22 |
240 |
126 |
19.6 |
| 80A |
80 |
185 |
150 |
22 |
270 |
136 |
22.6 |
| 100A |
100 |
210 |
175 |
24 |
300 |
153 |
30.9 |
| 125A |
125 |
250 |
210 |
24 |
350 |
180 |
49.2 |
| 150A |
150 |
280 |
240 |
26 |
400 |
205 |
64.9 |
| 200A |
200 |
330 |
290 |
26 |
480 |
242 |
103 |
Company
Qingdao Hongfeng Xianglong Valve Manufacturing Co., Ltd. is a professional marine valve manufacturing enterprise located in Mingcun Town, Pingdu City, Qingdao, China. We mainly produce marine valves and accessories like gate valve, globe valve, stop valve,check valve, stop-check valve, butterfly valve, ball valve, storm valve with Japanese, German, and national standards. Providing customers with high-quality and efficient products and services is our business philosophy, which we have always followed and continuously developed over the years.
The company's predecessor has been deeply involved in railway parts for 16 years, with rich processing technology and advanced processing equipment. It has an experienced professional team that can carry out specialized production from product design, mold development, product casting, processing, assembly, and testing. High quality products have won us the trust of customers, and good service has established a long-term cooperative relationship.
The company's factory has complete production and equipment, with an 8000 square meter production workshop and around 60 employees. It has a complete management team and management process, equipped with processing workshops, assembly workshops, pressure testing workshops, painting workshops, and complete valve production equipment such as lathes, milling machines, CNC machines, drilling machines, valve sealing test benches, and painting assembly lines. While ensuring internal quality, it provides customers with the shortest delivery time.
Workshop
Packaging & Shipping
FAQ
Q: Are you trading company or manufacturer ?
A: We are manufacturer in PingDu city, Qingdao city, China.
Q: What's your product range?
A: We produce marine valves, like gate valve, check valve, stop valve, stop-check valve, globe valve, ball valve, butterfly valve and accessories .
Q: What's Execution Standard?
A:JIS/GB/DIN/BS etc.
Q: What's your Strong product ?
A: Gate valve.
Q: How long is your delivery time?
A: Normally it is 3 days if the goods are in stock. or it is 35 days if the goods are not in stock, it is based on the quantity.
Q: Do you provide samples ?
A: Yes, we could offer the sample.
Q: What is your terms of payment ?
A: 30% deposit in advance and balance before shipment.
Q: What's the packing?
A: Plywood packing.
Q: Can I have my own logo on the products?
A: Yes, you can send us the drawing and we can make it.
Q: Can you produce the products based on my own drawing?
A: Yes.
Q: Which price terms can be accepted?
A: FOB,CIF etc.
Our Advantages
(1)Own production line and workshop to do all processes so can save cost and offer you competitive price.
(2)Own workshop to control schedule more flexibly.
(3)We can assure quality in every process in production line.
(4)Class Approval Certifications.
(5)Quality guarantee after sale.
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