BURKERT 20092884 (Type 6440) is a servo-assisted 2/2-way piston valve designed as a safety shut-off valve for fuel cell systems and other hydrogen applications. This specific model features a G 1/4 internal thread, an 8.00 mm orifice, and operates at a nominal pressure of 0 to 25 bar with a 24 V DC power supply. The stopper and core guide tube are welded together to ensure high pressure resistance, achieving a burst pressure of >250 bar for threaded bodies and an internal leakage rate of 1 x 10^-4 mbar l/s. The coils are molded with highly chemically resistant epoxy, and sliding rings are incorporated to increase the service life when used with dry gases.

General Technical Data

Feature	Specification
Seal Material	EPDM
Housing Material	Stainless steel 1.4404/316L
Coil Material	Epoxy (Thermal insulation class H)
Internal Leakage Rate	1 x 10^-4 mbar l/s (>1.5 bar differential pressure)
External Leakage Rate	1 x 10^-4 mbar l/s
Burst Pressure	>250 bar for flange and threaded body
Duty Cycle	100% continuous operation
Switching Time (DN 6, DN 8)	Opening: 10...20 ms / Closing: 40...50 ms
Operating Medium	Neutral gases (e.g., compressed air, nitrogen), optimized for hydrogen
Medium Temperature	-40 °C to +90 °C
Ambient Temperature	-40 °C to +55 °C / +75 °C for stationary applications depending on performance level
Degree of Protection	IP65 with cable plug Type 2518; IP6K9K with automotive plug

Power Reduction Requirement

Power must be reduced to 25% of the nominal power (holding phase) with the aid of current control or PWM signal after max. 500 ms (switch-on pulse) for mobile applications with increased ambient temperature.

Circuit Functions

• Circuit Function A (CF A): 2/2-way solenoid valve, servo-controlled, normally closed.

Approvals and Conformities

• Explosion Protection (Optional): Category 2 (Zone 1/21) and Category 3 (Zone 2/22) ATEX/IECEx approvals available for specific coil types.
• North America (USA/Canada): UL Listed for Hazardous Locations (E504714) and CSA approved as a Safety Shutoff Valve for hydrogen according to UL 429 and CSA 139.
• DNV GL Classification: Accepted for installation on all vessels classed by DNV GL (Ships, offshore units, high speed and light craft).

Materials

No.	Element	Material
1	Nut	Stainless steel 1.4305/303, PTFE-coated
2	Stopper	Stainless steel 1.4113/434
3	Core guide tube	Stainless steel 1.4303/305/308
4	Guide ring	PTFE carbon-filled
5	Core	Stainless steel 1.4113/434
6	Spring	Stainless steel 1.4310/301
7	Coil	Epoxide
8	Retaining plate	Stainless steel 1.4301/304
9	Body	Stainless steel 1.4404/1.4571/316L/316Ti
10	External seal	EPDM
11	Whole piston	Stainless steel 1.4305/303, PPS, PTFE carbon-filled, EPDM

Dimensions (Threaded Variant)

DN	A (Port Connection)	B [mm]	C [mm]	(D) [mm]	(E) [mm]	F [mm]	G	I [mm]	J [mm]	(P) [mm]	SW [mm]
6	G 1/4	12	40	61	71	18	M4	27	4.5	41.5	24
8	G 1/4	12	50	62	74	18	M4	27	4.5	42.5	24
12	G 1/2	14	55	96	110	42	5	62	36	-	36
16	G 3/4	16	99	115	-	-	-	-	-	-	-

Performance Specifications

Power Consumption (Kick and Drop coil AC/DC): The Kick and Drop coil features integrated electronics for short-term power increase and decrease in double coil technology.

Orifice (DN)	Coil Size [mm]	Cold Power Inrush [W] 500 ms	Cold Power Holding [W]	Warm Power Holding [W]
6 / 8	40 (6)	20	2	2
12 / 16	42 (K)	44	6.5	5.5