Mankenberg type DM 412
DN40/PN16/0.05-0.5bar/A216 WCB (GS-C25/1.0619)
I found this valve hidden in our despatch hall, waiting for shipment and felt the design kind of old-looking so I wanted to share the following background.
Basically it is a tankblanketing valve which is not produced anymore in this design, but our customer wanted an exact replacement for their existing one which was produced in 1983. The plant is revised now after 35 years of operation and (nearly) no maintenance.