Burkert 20142575 (Type 2933) is a 2/2-way diaphragm valve with a manually operated actuator. The manual actuator with a plastic handwheel (PPS) features a stainless steel diaphragm bonnet, ensuring suitability for hygienic or aggressive ambient conditions. The flow-optimised forged stainless steel 316L (1.4435 BN2) valve body with minimum dead space enables high flow values. This specific model features a DN 8 (NPS 1/4) welded connection (ASME BPE / DIN 11866 Series C) and a PTFE with EPDM backing membrane, supporting medium temperatures from -10 °C to +130 °C and pressures up to 10 bar.

The actuator has a compact, autoclavable design. It is equipped with an integrated visual position indicator and a single min-stroke limiter (closing limiter). This explosion-proof ATEX/IECEx device variant is suitable for demanding environments.

Approvals and Conformities

INFO

The product complies with the following approvals and conformities.

• Explosion Protection: ATEX (II 2 G Ex h IIC T4...T2 Gb, II 2 D Ex h IIIC T135°C...T300°C Db) and IECEx (Ex h IIC T4...T2 Gb, Ex h IIIC T135°C...T300°C Db). As a category 2 device suitable for zone 1/21 and zone 2/22.
• Foods and Beverages / Hygiene:
  • FDA: The PTFE/EPDM diaphragm complies with the Code of Federal Regulations published by the FDA.
  • USP: Tested according to United States Pharmacopeial Convention (USP) Class VI.
  • EC Regulation 1935/2004: Suitable for use with food and beverages.

Materials

No.	Element	Material
1	Handwheel	Polyphenylene sulphide (PPS)
2	Visual position indicator	Polyamide (PA), Stainless steel 1.4305
3	Valve spindle	Stainless steel 1.4305
4	Diaphragm bonnet	Stainless steel
5	Diaphragm	PTFE with EPDM backing membrane
6	Valve body	Forged stainless steel 316L/1.4435 BN2

Dimensions

Manual Actuator (Diaphragm Size 8)

Diaphragm size	H1	H2	∅ B
8	54	49	35

Forged Steel Valve Body (VS) with Welded Connection

ASME BPE / DIN 11866 Series C

Diaphragm size	Port connection DN	∅D1	s	L	h	H
8	1/4"	6.35	0.89	78	5.7	15.2

Performance Specifications

• Kv value (water): 0.7 m³/h (Measured at 20 °C, 4 bar at valve inlet and 3 bar at valve outlet)
• Maximum permitted medium pressure: 10 bar

Tightening Torques

WARNING

The following tightening torques refer to the static media pressures specified above. Excessive torque can shorten the service life of the diaphragm.

Diaphragm size	Medium pressure [bar]	Static Tightening Torque (PTFE) [Nm]	Dynamic Tightening Torque (PTFE) [Nm]
8	10	1.1	1.2

Installation

DANGER

Risk of injury due to high pressure and escaping medium. Switch off the pressure before working on the device or system. Vent or empty the lines.

Installation Position

Installation position is any, preferably with the actuator facing up. To ensure self-draining, the self-draining angle (α) depends on the valve body size and the inner diameter of the port connection. The marking on the port connection of the valve body serves as an orientation aid and must point upwards.

Setting Minimum Stroke Limit

This setting also serves as a closing limiter to protect the diaphragm. A hexagon nut is used to do this.

1. By turning the handwheel clockwise, the valve is moved to the closed position.
2. Loosen the screw on the handwheel (hexagon socket, width across flats 2) and remove the handwheel.
3. Screw the hexagon nut as far as it will go. Minimum stroke is set.
4. Mount the handwheel on the actuator.
5. Tighten the screw on the handwheel with 0.9 Nm.

Maintenance

TIP

After the first steam sterilisation, or when required, retighten the fastening screws crosswise.

The diaphragm is buttoned for diaphragm size 8.

1. Rotate the handwheel counterclockwise until it comes to a stop (OPEN position).
2. Loosen the fastening screws crosswise and remove the actuator with diaphragm from the valve body.
3. Rotate the handwheel clockwise until it comes to a stop (CLOSED position).
4. Unbutton the old diaphragm and button on a new diaphragm.
5. Rotate the handwheel counterclockwise until it comes to a stop (OPEN position).
6. Align the diaphragm. Identification tab is at a 90-degree angle to the flow direction.
7. Place the actuator together with diaphragm on the valve body and tighten the fastening screws crosswise in 3 stages (approx. 1/3, 2/3, 3/3 of the tightening torque: 2.5 Nm for PTFE size 8).