Product Overview

BURKERT 5281 is a servo diaphragm 2/2-way solenoid valve designed specifically for precise control of liquid or gas media. The product features an innovative construction that requires only one solenoid coil to adapt to all port size specifications, combining core advantages of water hammer-free operation and low noise, with short installation length and support for both threaded and flanged connection methods. Some models offer optional manual operation function, adapting to diverse installation requirements in industrial scenarios.

Key Features

• Easy Operation: Single solenoid coil adapts to the entire series of port sizes, simplifying selection and maintenance procedures.
• Stable Operation: Water hammer-free design reduces pipeline impact, low noise operation improves workplace comfort.
• Flexible Adaptation: Supports NC (normally closed) / NO (normally open) switching functions, optional NBR, EPDM, FKM seal materials, covering various media scenarios.
• Flexible Installation: Can be installed in any direction, recommended actuator upward installation for optimal performance; threaded and flanged versions meet different pipeline connection needs.
• Reliable Protection: IP65 protection rating, suitable for harsh industrial environments, ensuring long-term stable operation.

Technical Parameter Details

Basic Parameters

Parameter Category	Details
Valve type	2/2-way servo diaphragm solenoid valve
Switching function	NC (normally closed), NO (normally open)
Nominal diameter (DN)	13 mm, 20 mm, 25 mm, 32 mm, 40 mm, 50 mm, 65 mm
Port size	Threaded: G 1/2, G 3/4, G 1, G 1 1/4, G 1 1/2, G 2, G 2 1/2; Flanged: DIN 2501
Pressure range	0.2 - 16 bar (0.5 bar differential pressure required for complete switching)
Voltage specifications	24V DC, 24V 50-60Hz, 230V 50-60Hz, 110V 50Hz (non-standard voltages can be customized)
Operating mode	100% continuous duty (ED)
Response time	0.1 - 4 seconds (at 6 bar, +20°C conditions, opening: pressure from 0 to 90%; closing: pressure from 100% to 10%)

Temperature Parameters

Seal Material	Media Temperature Range	Special Notes
NBR	-10 to +80 °C	-
EPDM	-40 to +90 °C	Epoxy coil version up to +100 °C
FKM	-10 to +90 °C	Epoxy coil version up to +120 °C
-	Ambient temperature	Maximum +55 °C

Media Compatibility

Seal Material	Applicable Media
NBR	Neutral media, such as compressed air, water, etc.
EPDM	Oil-free and grease-free media
FKM	Hot air, aggressive solutions, etc.

Component Material Details

Component No.	Component Name	Material Specification	Notes
1	Coil	Polyamide (for NBR seal), Epoxy (for EPDM/FKM seal)	-
2	Plunger	1.4105 Stainless steel	-
3	Plunger seal	NBR, EPDM, FKM	Same as valve seal material
4	O-ring	NBR, EPDM, FKM	Same as valve seal material
5	End cover	Brass	-
6	Spring	1.4310 Stainless steel	-
7	Diaphragm	NBR, EPDM, FKM	Same as valve seal material
8	Body	Brass (threaded port), Cast iron (flanged port)	Threaded port complies with DIN EN 50930-6 standard

Dimensions

Threaded Port Version (Unit: mm)

DN	Port Size	B1 (Circuit Function A)	B1 (Circuit Function B)	B1* (With Manual Operation)	E1	F	L1
13	G 1/2	100.0	102.0	-	110	40	14
20	G 3/4	107.5	109.5	-	117.5	60	16
25	G 1	116.0	118.0	159.5	126.0	70	18
32	G 1 1/4	126.5	128.5	171.5	136.5	85	20
40	G 1 1/2	135.5	137.5	180.5	145.5	85	22
50	G 2	157.2	159.2	204.7	167.2	115	24
65	G 2 1/2	157.2	159.2	-	167.2	115	27

Flanged Port Version (Unit: mm)

DN	Port Size	B2 (Circuit Function A)	B2* (With Manual Operation)	G	L2
25	DIN 2501	115	169.5	120	160
32	DIN 2501	126	181.5	140	180
40	DIN 2501	126	190.5	150	200
50	DIN 2501	164	214.7	165	230

Note: The total height B1 for circuit function B is 2 mm higher than circuit function A; versions with manual operation are marked as B1*, B2*.

Models and Ordering Information

Threaded Port (Brass Body, Without Cable Plug)

Circuit Function	Seal Material	Port Size	DN (mm)	Kv Value (m³/h)	24V DC Model	24V 50-60Hz Model	230V 50-60Hz Model
NC (A)	NBR	G 1/2	13	4.0	134 317	134 318	134 320
NC (A)	NBR	G 3/4	20	6.4	134 321	134 322	134 324
NC (A)	NBR	G 1	25	10.0	134 325	134 326	134 328
NC (A)	EPDM	G 1/2	13	4.0	134 373	134 374	134 376
NC (A)	FKM	G 1/2	13	4.0	134 345	134 346	134 348
NO (B)	NBR	G 1/2	13	4.0	178 873	178 872	178 874
NO (B)	NBR	G 3/4	20	6.4	178 876	178 875	178 877

With Manual Operation (Threaded Port, Brass Body, Without Cable Plug)

Circuit Function	Seal Material	Port Size	DN (mm)	Kv Value (m³/h)	24V DC Model	24V 50-60Hz Model	230V 50-60Hz Model
NC (A)	NBR	G 1/2	13	4.0	139 307	139 308	138 314
NC (A)	NBR	G 3/4	20	6.4	139 309	139 310	139 311
NC (A)	NBR	G 1	25	10.0	139 312	139 313	138 801

Flanged Port (Cast Iron Body, Without Cable Plug)

Circuit Function	Seal Material	Port Size	DN (mm)	Kv Value (m³/h)	24V DC Model	24V 50-60Hz Model	230V 50-60Hz Model
NC (A)	NBR	DIN 2501	25	10.0	134 401	134 402	134 404
NC (A)	NBR	DIN 2501	32	20.0	134 405	134 406	134 408
NC (A)	NBR	DIN 2501	50	40.0	134 413	134 414	134 416

Spare Parts Information

Spare Part Name	Model/Specification	Compatible Products	Included Components
Cable plug	Type 2508	Type 5281 full series	Flat washer, fixing screws
Fixing screws	Standard accessory	Type 2508 cable plug	Supplied with cable plug
Flat washer	Standard accessory	Type 2508 cable plug	Supplied with cable plug

Note: Cable plug must be ordered separately. For other non-standard cable plug versions (complying with DIN EN 175301-803 Form A), please refer to Type 2508 separate data sheet.

Certifications and Compliance

The product has passed UL/UR/CSA certification, UL fire safety certification and European gas certification, complying with industrial safety and environmental standards, suitable for use in various industrial scenarios.

Installation and Usage Recommendations

1. Installation direction can be chosen arbitrarily, actuator upward installation is recommended to ensure optimal performance.
2. Ensure media compatibility with the selected seal material to avoid leakage or damage due to material mismatch.
3. Electrical connection must use Type 2508 cable plug to ensure protection rating compliance.
4. Working pressure must meet 0.2 - 16 bar range, complete switching requires 0.5 bar differential pressure.
5. Special application scenarios (such as non-standard voltage, NPT/Rc ports) can contact the manufacturer for customization.