The BURKERT 20085151 (Type 2933) is a 2/2-way manually operated diaphragm valve designed for hygienic and sterile applications. It consists of a manually operated actuator with a PPS handwheel, an EPDM high-temperature diaphragm, and a flow-optimized 316L stainless steel tube valve body with minimum dead space. The manual actuator features a compact, autoclavable design and is equipped with an integrated visual position indicator, a reproducible stroke scale, and an adjustable closing limiter. This specific configuration features a DN 25 welded connection and is suitable for neutral gases and liquids, highly purified, sterile, or aggressive media up to 10 bar and 143 °C.

General Technical Data

Feature	Specification
Valve body material	Stainless steel tube 1.4435-BN2 / UNS S31603 (316L) according to DIN 11866, ASTM A269 / A270, DIN EN 10217-7 / 10216-5
Diaphragm material	EPDM high-temperature (AD)
Actuator material	Handwheel: PPS; Diaphragm bonnet: Stainless steel
Standard surface quality	Internally electrically polished: Ra ≤ 0.38 μm (ASME BPE SF4 / DIN HE4); Externally electrically polished
Operating medium	Neutral gases and liquids, highly purified, sterile, aggressive or abrasive mediums
Medium temperature	-10...+143 °C (steam sterilisation +150 °C for 60 min)
Ambient temperature	-10...+130 °C (short-term up to +150 °C), autoclavable
Port connection	Welded connection (DIN 11850-2 / DIN 11866 series A / DIN EN 10357 series A)

Approvals and Conformities

• FDA: The EPDM diaphragm complies with the Code of Federal Regulations published by the FDA (Food and Drug Administration, USA).
• USP: The EPDM diaphragm is tested according to United States Pharmacopeial Convention (USP) Class VI.
• EC Regulation 1935/2004: The EPDM diaphragm is suitable for use with food and beverages according to EC Regulation 1935/2004/EC.

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 1.4308
5	Diaphragm	EPDM (AD)
6	Valve body	Stainless steel tube 316L/1.4435 BN2

Dimensions

Tube Valve Body (VP) with Welded Connection

DIN 11850-2 / DIN 11866 series A / DIN EN 10357 series A

Diaphragm size	Port connection DN	∅D1	s	L	h	H	Product key
15	15	19	1.5	110	13.20	22.7	SD42
15	20	23	1.5	119	15.20	26.7	SD43
20	25	29	1.5	129	18.20	32.7	SD44
25	32	35	1.5	148	21.20	38.7	SD45

(Note: Dimensions in mm. The 20085151 model corresponds to Diaphragm size 20, DN 25).

Performance Specifications

Flow Characteristics

Diaphragm size	Port connection DN	Kv value water [m³/h]
20	25	14.9

(Note: Flow rate Kv value water for elastomer diaphragms. Measurement at +20 °C, 4 bar at valve inlet and 3 bar at valve outlet).

Medium Pressure

Diaphragm size	Maximum static operating pressure [bar]	Tightening torque for max static pressure (EPDM) [Nm]
20	10	0.9

WARNING

The tightening torques refer to the static media pressures specified above. Excessive torque can shorten the service life of the diaphragm. A tolerance of +10% applies to the tightening torques specified.

Operation and Installation

Position Indicator

Turning the handwheel counterclockwise reveals the yellow position indicator and the scale marked on it as the valve opens further. The scale on the handwheel determines the rotation position of the handwheel (30 positions). 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. 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. The square on the spindle and the hexagon head of the nut must be correctly aligned.
5. Tighten the screw on the handwheel with 0.9 Nm.

TIP

To protect the actuator, we recommend not closing the actuator with more force than is required to close the valve tightly.