The WBC lift check valve is designed according to DIN 3840, PN150 and DN50 and can be applied in an environment under 15 Mpa. What's more, the lift check valve is also referred to as a piston check valve.
Features
1. Compact but extremely sturdy design for high pressure & temperature service;
2. Bolted cover design, easy to open;
3. Piston type body guide disc;
4. Perfect match of disc & seat ring;
5. Other body or trim material optional.
Technical Drawing

Witnessing tests 
Source: https://www.kellyvalve.com/din-3840-lift-check-valve-dn50-pn160-astm-a216-wcb.html