Hynautic MSV-21 950 PSI Relief Valve

Hynautic MSV-21 950 PSI Relief Valve

Inline Relief Valve for Hydraulic Steering Systems

The Hynautic MSV21 is a high-pressure inline relief valve used to protect hydraulic steering system components from overpressure and to assist with air purging during installation or service. Built with 1/4"-18 NPTF ports and rated to 950 PSI, this valve is a direct-fit component for many Hynautic and other marine hydraulic systems.

Key Features

• 950 PSI Relief Setting – Helps prevent system over-pressurization
• Aids in Air Purging – Easy-access valve screws for quick purge procedures
• Inline Mount Design – Mount above the cylinder to optimize bleeding process
• Brass Screw Access – Valve must be accessible after installation
• Durable Construction – Designed for marine hydraulic systems

Specifications

Installation Notes

• Mount Position: Always mount the valve above the cylinder to aid in purging
• Orientation: Position with brass screws facing up for service access
• Post-Purge: Tighten valve screws fully after purging—failure to do so can cause loss of steering
• Sealants: Use approved hydraulic sealants only; avoid introducing dirt or debris
• Purge Access: Ensure 1/2" hex fittings can be backed off easily for air release

Diagram Reference (from Manual)

• Mounting holes: 2.06" center to center
• Overall height: 3.88"
• Relief screw hex: 1/2"
• Port Configuration: 3x 1/4"-18 NPTF

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• Seatech Marine Products, Inc. is an authorized dealer and service center for Hynautic. Formerly manufactured by Teleflex Seastar, Hynautic is now manufactured in the US as its own brand.

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