Specifications:
The document provides specifications for the Dual Plate Wafer Check Valve by Athena Engineering S.R.L. The valve is designed for various applications including HVAC, water supply, sewage, chemical, petrochemical processing, power utilities, paper and pulp, and shipbuilding. It supports different flange standards such as DIN, BS, UNI, ISO, and ANSI.

Working Pressure:
- DN50-450: PN16 (200 PSI)
- DN500 and above: PN10 (150 PSI)

Design Features:
- The valve features dual plates that ensure a full seal for bubble-tight shutoff.
- The body is wafer type with a plain face, designed to be small and light for easy installation between different standard pipe flanges.
- Dual corrosion-resistant springs activate the check valve plates and distribute load force evenly, ensuring a quick and sure response.
- The body seat offers a choice of several different elastomer compounds to meet various application demands.

Materials:
The document lists standard materials for the main parts of the valve:
- Body: Cast Iron, Ductile Iron
- Disc: Ductile Iron + Ni, CFB, CFBM, Bronze
- Shaft: Stainless Steel
- Hinge Pin: Stainless Steel
- Plug: Carbon Steel
- Body Bearing: PTFE
- Spring Bearing: PTFE
- Stop Pin: Stainless Steel
- Eye Bolt: Carbon Steel
- Body Seat: NBR, EPDM, Viton, Neoprene

Dimensions and Weights:
The document provides detailed dimensions and weights for various sizes of the valve, ranging from DN50 to DN800, with corresponding measurements for face-to-face dimensions, flange dimensions, and weights.