Oil draining devices for oil type transformer- Din 42551 / DownloadDescription
Oil Drain Valves – DIN 42551 / EN 50216-4 are essential components used in oil-immersed power and distribution transformers. These valves are welded to the bottom of transformer tanks and serve two primary purposes: the controlled discharge of transformer oil and the safe collection of oil samples for analysis.
Manufactured in full compliance with DIN 42551 and EN 50216-4 standards, these valves ensure reliable performance in demanding environments. They are fully compatible with DIN 42551 F-type oil drain mechanisms and act as an intermediary component between the tank and drain fittings. Commonly installed on the base of transformer tanks, these valves are engaged during routine maintenance or oil replacement operations.
The oil drain valves are available in three standard sizes:
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NW 22 (A22)
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NW 31 (A31)
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NW 40 (A40)
These sizes accommodate various system requirements depending on oil flow and connection standards. The valve body is manufactured from ST37 carbon steel, and the cover is typically made of GG20 cast iron. For harsh or corrosive environments, optional covers in AISI 304 or AISI 316 stainless steel are also available. The locking plug is produced from brass, ensuring durability and long-term use.
A key feature of these valves is their sealing configuration. DIN 42551 provides three standard sealing forms:
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Form A – Metal-to-metal sealing; long-lasting and maintenance-free.
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Form OR – O-ring sealing; preferred for high-precision applications.
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Form C – Conical sealing; ensures high tightness in open-close movements.
These valves prevent oil leakage during discharge, making them environmentally friendly and safe for maintenance personnel. In addition to oil drainage, they provide a secure port for sampling transformer oil during routine inspections or condition monitoring.
Hann Metal’s oil drain valves undergo rigorous sealing and pressure tests before shipment. Each unit is engineered to match the tank flange dimensions precisely, ensuring easy welding and long-term reliability in transformer systems.
Applications:
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Power transformers
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Distribution transformers
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Energy production and transmission facilities
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Industrial substations
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EPC energy infrastructure projects
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Maintenance service workshops
Why Choose Hann Metal?
Our oil drain valves meet not only the dimensional and sealing requirements of DIN 42551 but are also proven in field conditions. Built from high-quality materials and tested under real operating pressures, these valves offer leak-proof performance, ease of installation, and long service life. Technical documentation and drawing support are available upon request for every product in our catalog.
For detailed technical drawings, quotations, or application support, feel free to contact our expert team.
