Product Description
Marine Stop Valve - Definition & Function
A marine stop valve is a manually operated isolation valve designed to completely shut off or permit fluid flow in shipboard piping systems. Unlike regulating valves, its primary purpose is positive flow isolation rather than flow control. These valves are critical for maintenance, emergency shutdowns, and system reconfiguration aboard vessels.
Key Characteristics of Marine Stop Valves
1. Design & Operation
- Linear Motion Mechanism: Features a rising stem that moves perpendicular to flow when operated (via handwheel or actuator)
- Metal-to-Metal Sealing: Typically uses tapered plug or disc that seats firmly against the valve body
- Multi-Turn Operation: Requires several rotations (3-5 full turns) from open to closed position
2. Material Specifications
- Body Materials: Bronze (for seawater), cast steel (high pressure), stainless steel (corrosive media)
- Trim Components: Stellite-hardened seats, graphite packing for stem sealing
- Pressure Classes: Ranging from 150# to 2500# depending on system requirements
3. Marine-Specific Features
- Backseat Design: Allows repacking under pressure when fully open
- OS&Y (Outside Stem & Yoke): Visual position indication critical for marine engineers
- Fire-Safe Certification: Required for fuel oil and flammable service per SOLAS regulations
Primary Marine Applications
- Fuel Oil Systems: Bunker line isolation, transfer operations
- Sea Water Services: Main cooling water shutoff, firemain isolation
- Hydraulic Systems: Power fluid isolation for steering gear/macinery
- Compressed Air: Emergency shutdown for pneumatic systems
Comparison with Other Marine Valves
| Feature |
Stop Valve |
Gate Valve |
Globe Valve |
| Flow Regulation |
Not recommended |
Poor |
Excellent |
| Pressure Drop |
Moderate |
Very Low |
High |
| Sealing |
Bubble-tight |
Good |
Excellent |
| Maintenance |
Easy (repackable) |
Difficult |
Moderate |
| Cost |
Moderate |
Low |
High |
Operational Advantages in Marine Service
- Positive Shutoff: Meets class requirements for critical isolation points
- Maintenance Friendly: Designed for in-situ servicing without line removal
- Position Verification: Rising stem provides visual open/close confirmation
- Emergency Ready: Quick-closing variants available for safety systems
Selection Considerations
- Pressure-Temperature Rating: Must match system design conditions
- End Connections: Flanged (ASME B16.5/16.24), threaded (NPT/BSP), or butt-weld
- Actuation Requirements: Manual, gear-operated, or actuated for remote systems
- Class Approval: ABS, DNV, LR, or other classification society certification
Note: Modern marine designs often use stop valves in conjunction with bypass lines and double block-and-bleed configurations for critical services.
Would you like specific information about stop valve installation best practices or classification society requirements?
| seating ring |
welding scs304 |
| seating ring |
welding scs304 |
Company Profile
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.
Company
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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