Technical specifications of butterfly valves

DN : NPS : NB : Pipe size : Pipe diameter : Steel : Plastic : Copper : Thread in inches

DN - nominal diameter. The numerical designation of the internal diameter common to all components of a pipeline system except for those characterized by their external diameters. The nominal diameter is used to standardize the size of pipeline fittings, has no unit of measurement, and is approximately equal to the internal diameter of the connecting pipeline.

PN - nominal pressure. The maximum excess pressure of the working medium at a temperature of 20°C at which continuous operation is allowed and the calculated service life of the butterfly valve is provided.

Test pressure. The excess pressure at which a hydraulic test of the butterfly valve for strength and tightness with water should be carried out at a temperature of 5 to 70°C if no other test temperature is specified in the passport or normative documentation.

Operating pressure. The maximum excess pressure at which the specified operating mode of the butterfly valve is ensured, taking into account the actual temperature of the working medium. The operating pressure value is usually less than the nominal pressure value, so operation at maximum working temperature and nominal pressure of the medium is not allowed.

Kvs - flow coefficient. Numerically equal to the water flow rate, in m³/h at a temperature of 20°C, at which the pressure drop across the disk valve will be 1 bar. The value of the flow coefficient is used in hydraulic calculations to determine pressure losses on elements of the pipeline system.

Leakage class - defines the maximum permissible leakage through a closed disk valve at atmospheric pressure on one side and water pressure of 1.1*PN on the other side. The water temperature during testing should be in the range of 5 to 40°C.

Class A - leakage is absent
Class B - no more than 0.0006*DN(mm) cm³/min
Class C - no more than 0.0018*DN(mm) cm³/min
Class D - no more than 0.006*DN(mm) cm³/min

Technical specifications of butterfly valves

Material Compatibility Table of Butterfly Valve Seat (Seal Ring)

Medium	Code	Seal Material	Application	Operating Temperature Range
Potable water	EPDM	DRINKING WATER EPDM	WRAS, ACS. Certified by DVGW GmbH (DVGW W 363-P)	-20°C .. +90°C
Potable water Heating water	EPDM	DRINKING WATER EPDM-HT (EPDM-019)	For potable water purification, treatment and distribution - higher temperature resistance	-20°C .. +130°C
Beverages Juices Malt Hot service	EPDM	EPDM-HT*) (EPDM-022)	FDA certified. For sugar mills, beverage factories, malt houses. Seat colour - black.	-20°C .. +130°C
Beverages Juices Malt	EPDM	EPDM-014 (FDA)	FDA certified - for lower tempetaure ranges. Seat colour - white. Corresponds to standard 1935/2004.	-10°C .. +90°C
Air Non-aggressive acids and alkalines Non-aggressive minerals Water distribution	EPDM	EPDM-008/1	For distribution of non-aggressive mild mineral acids, air distribution - ventilation and air conditioning. Suitable for water treatment installations.	-20°C .. +90°C
Gas	NBR	DVGW-GAS NITRILE	For natural gas transport and distribution. Certificated by DVGW CERT GmbH	-10°C .. +60°C
Abrasive media	NBR-X	CARBOXYLIC NITRILE	For oily media applications with present abrasive particles in transported media. Certified by FDA.	0°C .. +90°C
Abrasive media	FLUCAST	FLUCAST AB/N	For oily media installations - crude oil distribution	0°C .. +90°C
Abrasive media	FLUCAST	FLUCAST AB/E	For abrasive resistant applications - for wet media like sludges etc.	-5°C .. +90°C
Abrasive media	FLUCAST	FLUCAST AB/P	For abrasive resistant applications - for dry media like loose materials, powder media (gypsum, carbon black, china clay, oxides), pneumatic conveying of cement and powder in mining industry.	-10°C .. +70°C
Abrasive media	FLUCAST	FLUCAST AB/T	For abrasive media with high temperature resistance.	-5°C .. +130°C
Salt water Biogas Oil Fuel	ECO	EPICHLOR- HYDRIN	For use with seawater, salt water, gas/biogas, oil, and fuel.	-40°C .. +90°C
Steam Water Biogas Aggressive acids Oils	FPM	VITON	High fluorine content, resistant to acids and oils, chemically stable.	-5°C .. +150°C
Industrial grease Oils Non-aggressive acids	CSM	HYPALON	For standard applications with rubber compounds; service life is limited by high temperatures — for oil distribution, diluted acids and alkalis.	-10°C .. +100°C
Steam Water	MVQ	HYPALON	For heat recovery, steam supply and distribution systems.	-40°C .. +150°C
Food-grade steam	VMQ	FOOD SILICONE	Steam distribution systems with elevated operating temperatures, FDA certified.	-40°C .. +150°C
Steam / Water – high temperature	VMQ	SILICONE	For media requiring high thermal resistance at both negative and positive temperatures (steam).	-40°C .. +160°C