The Burkert Type 2935 manually operated diaphragm valve consists of a manually operated actuator, a diaphragm, and a tank bottom valve body. The manual actuator with a plastic or stainless steel handwheel is available with a diaphragm bonnet made of stainless steel or plastic, ensuring use in hygienic or aggressive ambient conditions. The flow-optimized valve body with minimum dead space enables high flow values and a wide range of possible applications. The actuator has a compact, autoclavable design and is equipped with an integrated visual position indicator, a reproducible stroke scale, and an adjustable closing limiter.

Approvals and Conformities

• Explosion Protection: ATEX / IECEx (Category 2 device suitable for zone 1/21 and zone 2/22).
• Foods and Beverages/Hygiene: FDA compliant, USP Class VI tested, 3-A Sanitary Standards Inc. compliant, and suitable for use with food and beverages according to EC Regulation 1935/2004.

Materials

No.	Element	Material
1	Handwheel	Polyphenylene sulphide (PPS), stainless steel 1.4308
2	Visual position indicator	Polyamide (PA), stainless steel 1.4305
3	Valve spindle	Stainless steel 1.4305
4	Diaphragm bonnet	Stainless steel 1.4308, polyphenylene sulphide (PPS)
5	Diaphragm	EPDM (AD), PTFE/EPDM (EA), advanced PTFE/EPDM (EU), laminate of GYLON® and EPDM (ER)
6	Valve body	Stainless steel block material 1.4435 according to DIN EN 10088 and 316L according to ASME BPE

Technical Data

Medium Temperature

• EPDM (AD): -10...+143 °C (steam sterilisation + 150 °C for 60 min)
• PTFE/EPDM (EA): -10...+130 °C (steam sterilisation + 140 °C for 60 min)
• Advanced PTFE/EPDM (EU): -5...+143 °C (steam sterilisation + 150 °C for 60 min)
• Laminate of GYLON® and EPDM (ER): -5...+130 °C (steam sterilisation + 140 °C for 60 min)

Maximum Permitted Medium Pressure

Diaphragm size	EPDM/FKM [bar]	PTFE/advanced PTFE/GYLON® [bar]
8...40	10	10
50	7 / 10 (10 for SS actuator)	7 / 10 (10 for SS actuator)
65...80	10	10
100	6	6

Dimensions

Manual Actuator with Tank Bottom Body

Diaphragm size	C2 [mm]	C3 [mm]
15	103	101
20	116	115
25	127	129
40	182	201
50	203	217
65	265	305

Tank Bottom Body with Welded Connection

(Dimensions vary by standard: DIN EN ISO 1127, DIN 11850-2, ASME BPE, SMS 3008. Refer to full documentation for complete dimensional tables.)

Tank Bottom Body with Clamp Connection

(Clamp dimensions must be added to the welded connection dimensions.)

Installation and Maintenance

Welding Tank Bottom Body

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.

Recommendations for welding:

1. Weld the tank bottom body to the container base before the container is assembled. Weld the tank bottom body in the middle of the container base so that the container can be optimally drained.
2. Weld the tank bottom body into the pipeline. Ensure that pipelines are in alignment and properly supported.

WARNING

To prevent damage: Dismantle the actuator and diaphragm before welding or bonding the valve body.

Replacing the Diaphragm

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 or unscrew the old diaphragm. When fastening with a bayonet catch, loosen the diaphragm by rotating it 90°.
5. Install a new diaphragm in the actuator.
6. Tighten each fastening screw in 3 stages (approx. 1/3, approx. 2/3, 3/3 of the tightening torque) crosswise.

DANGER

Explosion hazard due to electrostatic charge! If the device is used in a potentially explosive area (ATEX), ensure the actuator and valve body are properly grounded to prevent static buildup. Only use approved cleaning agents.