BURKERT 20093515 (Type 2933) 2/2-way manual diaphragm valve consists of a manually operated actuator, a PTFE with EPDM backing diaphragm, and a 2-way investment cast 316L/1.4435 valve body with a DN 25 (1") ASME BPE clamp connection. The manual actuator with a PPS (Polyphenylene sulphide) handwheel ensures reliable use in hygienic or aggressive ambient conditions.

The flow-optimized valve body with minimum dead space enables high flow values. The actuator has a compact, autoclavable design and features an integrated visual position indicator and a single min-stroke limiter (closing limiter) to protect the diaphragm.

Approvals and Conformities

• 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 1935/2004: Suitable for use with food and beverages.
• Explosion Protection: ATEX / IECEx suitable for zone 1/21 and zone 2/22 (as category 2 device).

Material Specifications

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	Polyphenylene sulphide (PPS)
5	Diaphragm	PTFE with EPDM backing membrane
6	Valve body	Investment cast material 316L/1.4435

Dimensions

Manual Actuator

Note: Dimensions in mm.

Diaphragm size	H1	H2	∅ B
25	101	90	45

Cast Valve Body (VG) with Clamp Connection

Note: Dimensions in mm.

Diaphragm size	Port connection Inch	∅D1	s	∅D2	L	h	H
25	1" (ASME BPE)	25.4	1.65	50.5	114	18.0	40.0

Performance Specifications

Flow Characteristics and Medium Pressure

WARNING

Excessive torque can shorten the service life of the diaphragm. A tolerance of +10% applies to the tightening torques specified.

Diaphragm size	Kv value water [m³/h]	Max static operating pressure [bar]	Tightening torque (PTFE) [Nm]
25	14.6	10	3.5

Installation and Operation

Position Indicator

Turning the handwheel counterclockwise reveals the yellow position indicator and the scale marked on it as the valve opens further. The stroke scale shows the relative position of the valve and serves as a fixation point for determining the rotation position.

Setting Minimum Stroke Limit

A minimum stroke limit can be set for Type 2933. This setting also serves as a closing limiter to protect the diaphragm.

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.

WARNING

Do not screw the hexagon nut in the area of the square. Only use minimum stroke limit in the 0…25 % opening stroke range.

Maintenance

Replacing the Diaphragm

For diaphragm size 25, the diaphragm is fastened with a bayonet catch and threaded connection.

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. Loosen the PTFE diaphragm by turning it 90°.
5. Install a new diaphragm in the actuator.
6. Rotate the handwheel counterclockwise until it comes to a stop (OPEN position).
7. Align the diaphragm. Identification tab is at a 90-degree angle to the flow direction.
8. Place the actuator together with diaphragm on the valve body.
9. Tighten each fastening screw in 3 stages crosswise (Tightening torque for size 25 PTFE: 6 Nm).