Mepco (Dunham Bush) ML5970 Valve

As a technician, you know that keeping a steam or hydronic system balanced starts with a reliable isolation point. The Mepco (Dunham Bush) ML5970 Valve is a 1/2" 740A-ST-1 straight pattern radiator valve engineered specifically for high-demand commercial and industrial heating applications. Built with a heavy-duty bronze body, this manual valve provides positive on/off control for radiators and heating elements across a wide pressure range, from 25" vacuum up to 125 PSI for steam (15 PSI WSP) and up to 200 PSI for water systems. The 740A-ST-1 model features a packless design, utilizing a heavy-duty coiled spring and a one-piece formed packing ring to ensure a leak-proof seal around the stem without the frequent maintenance of traditional packed valves. This 1/2" NPT manual radiator valve is the standard for contractors looking for a direct replacement in Dunham-Bush legacy systems, ensuring HVAC system compatibility and long-term performance in both vacuum and low-pressure steam environments.

Key Benefits for Technicians:

• Durable Construction: The high-quality bronze body and brass trim resist corrosion in harsh steam environments.
• Maintenance-Free Operation: The packless spring-loaded design eliminates the need for frequent repacking and prevents stem leaks.
• Versatile Application: Suitable for steam heating (low pressure and vacuum) as well as hot or chilled water systems.
• Precise Control: Features a heavy packing nut and a dial-indicated handle for easy adjustment and visible flow status.
• Standard Fitting: 1/2" NPT female inlet and union/male NPT nipple outlet allow for straightforward installation into existing piping.

Common Questions & Technical Support:

Can I use the ML5970 for both steam and hot water?
Yes, the Mepco 740A series is designed for steam systems up to 125 PSI and hydronic systems up to 200 PSI, making it a versatile choice for mixed-use mechanical rooms.

What is the difference between an angle and a straight pattern valve?
The straight pattern (740A-ST-1) is used when the supply piping is perfectly aligned with the radiator inlet. For perpendicular piping, an angle pattern would be required.

Does this valve require an actuator?
This is a manual radiator valve. If your system requires automated temperature control, you may need a thermostatic radiator valve (TRV) body and a separate actuator.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.