Bürkert 456902 (Type 5282) is a servo-assisted 2/2-way diaphragm valve designed for controlling, shutting off, and metering neutral media. A minimum differential pressure of 0.2 bar is required for the valve to function properly. This specific model features a robust brass body, 1 1/4" NPT internal thread connections, and operates on 24V DC. It is equipped with an NBR seal suitable for temperatures from 0 °C to +80 °C and includes a service-friendly manual override for start-up and testing.

The 3/2-way pilot valve can be easily converted from a Normally Closed (NC) to a Normally Open (NO) circuit function by rotating it on the armature. The solenoid coils are moulded with a chemically resistant epoxy, ensuring durability in demanding industrial environments. When correctly connected with a suitable cable plug (e.g., Bürkert Type 2508), the device satisfies IP65 protection class requirements.

Key Features

• Servo-assisted diaphragm valve: Suitable for orifices up to DN 65.
• Separating diaphragm: Designed for aggressive and contaminated media.
• Adjustable switching times: Closing and opening times can be adjusted individually via side throttle screws.
• Manual override: Standard feature for easy commissioning and maintenance.
• Convertible circuit function: Easily switch between NC and NO by rotating the pilot valve.

Technical Data

Property	Value
Model	456902 (Type 5282)
Circuit Function	A - normally closed (NC)
Port Connection	1 1/4" NPT Internal thread
Orifice (Main Valve)	32.0 mm
Kv Value (Water)	20 m³/h
Operating Voltage	24 V DC
Pressure Range	0.2 - 10 bar
Body Material	Brass
Seal Material	NBR (Nitrile rubber)
Medium Temperature	0 °C to +80 °C
Ambient Temperature	Max. +55 °C
Duty Cycle	100% continuous operation
Degree of Protection	IP65 (with suitable connector)
Approvals	UL Recognized, CSA

Circuit Functions

The 456902 model is configured as Circuit Function A (Normally Closed) by default, but the pilot valve can be rotated to achieve Circuit Function B (Normally Open).

Symbol	Description
	Circuit function A (CF A) 2/2-way solenoid valve Servo-controlled, with manual override Normally closed

Material Specifications

No.	Element	Material
1	Coil	Epoxy
2	O-ring	NBR, EPDM, FKM
3	Cover	Brass (DN 13 stainless steel 1.4408/316, DN 20...DN 50 stainless steel 1.4581/316CB)
4	Spring	Stainless steel 1.4310/302
5	Diaphragm	NBR, EPDM, FKM
6	Diaphragm holder	Brass, stainless steel 1.4401 /316
7	Valve body	Brass (DN 13 stainless steel CF3M, DN 20...DN 50 stainless steel 1.4581/316CB)
8	Manual override	PA

Dimensions

Note: Dimensions in mm. The dimensions D2 and F2 apply to NPT thread.

DN	A1	B1	NPT (D2)	NPT (F2)	E1	L1	SW
32	122.0	147.0	NPT 1 1/4	17.3	85	126	50

Installation and Operation

Risk of injury from high pressure

Before loosening the pipes and valves, turn off the pressure and vent the pipes.

Risk of injury due to electrical shock

Before reaching into the device or the equipment, switch off the power supply and secure to prevent reactivation. Always connect the protective conductor and check electrical continuity between coil and body.

Manual Emergency Actuation

INFO

When the manual emergency actuation is locked, the valve can no longer be actuated electrically.

Changing Valve Function

The delivery condition corresponds to the order key. Turning the pilot valve through 180° changes the circuit function of the valve.

TIP

The circuit function can only be changed for variants up to 10 bar.

• Function NC: The pilot valve is installed in such a way that the manual emergency actuation points in the direction opposite to the direction of flow arrow.
• Function NO: The pilot valve is installed in such a way that the manual emergency actuation points in the same direction as the identification for the flow direction.

Setting the Switching Times

The closing and opening times of the valve can be changed if required with the side throttle screws.

Pressure surges caused by liquid media

If closing times are fairly short, liquid media cause higher pressure surges. These may reduce the service life of the diaphragm and destroy other devices and components in the system. Discharge of medium can occur if the throttle screws are unscrewed too far.