BURKERT 20075525 (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 reliable use in hygienic or aggressive ambient conditions. The flow-optimised 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.

This specific configuration (SKU 20075525) features a DN 150 Bürkert-tank bottom flange, an EPDM high-temperature diaphragm (size 40), and a stainless steel block body (1.4435 / 316L). It is rated for pressures up to 10 bar and is fully CIP/SIP capable, meeting stringent food and pharmaceutical standards including FDA and USP Class VI.

General Technical Data

Feature	Specification
Block body material	Stainless steel block material 1.4435 (DIN EN 10088) and 316L (ASME BPE)
Diaphragm material	EPDM high-temperature
Actuator material	PPS (Polyphenylene sulphide) handwheel, Stainless steel bonnet
Standard surface quality	Internally electrically polished: Ra ≤ 0.38 μm (ASME BPE SF4/DIN HE4)
Medium temperature	-10...+143 °C (steam sterilisation +150 °C for 60 min)
Ambient temperature	-10...+130 °C (short-term up to +150 °C), autoclavable
Nominal pressure	0 - 10 bar (PN 16 / Class 150)

Approvals and Conformities

• Explosion Protection (ATEX/IECEx): Suitable for Zone 1/21 and Zone 2/22 as a category 2 device (Ex h IIC T4...T2 Gb / Ex h IIIC T135 °C...T300 °C Db).
• Food and Pharma: FDA compliant, USP Class VI compliant, EC Regulation 1935/2004 compliant, 3-A Sanitary Standards Inc.
• Certificates: Manufacturer's test certificate 3.1 included.

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

Dimensions

Manual Actuator with Tank Bottom Body

(Dimensions in mm, unless otherwise stated)

Diaphragm size	C2	C3
8	69	71
15	103	101
20	116	115
25	127	129
40	182	201
50	203	217
65	265	305
80	336	278
100	300	370

Tank Bottom Body with Welded Connection

Tank Bottom Body with Clamp Connection

INFO

Clamp dimensions must be added to the welded connection dimensions.

Installation and Welding

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.

Welding Tank Bottom Body Recommendations

Observe the following sequence:

1. Weld the tank bottom body to the container base before the container is assembled. It is possible to weld onto a ready-assembled container but it is more difficult. Note: 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.
   • Support and align pipelines. To ensure that the pipeline is self-draining, we recommend the inclination angles according to the valid ASME BPE.

TIP

For information on containers and instructions for welding, refer to the ASME VIII Division I standard. Check the batch number indicated on the manufacturer’s certificate 3.1 supplied before starting welding work.

WARNING

Before welding, note the following:

• Only use welding materials which are suitable for the tank bottom body.
• The tank bottom valve must not collide with any other installation part. The actuator must be easy to install and remove.
• Dismantle the actuator and diaphragm before welding or bonding the valve body to prevent damage.

Performance Specifications

Maximum Permissible Tightening Torque for the Handwheel

WARNING

Turn the handwheel only until you can feel the valve closing. Do not tighten any further. The diaphragm may be damaged.

Diaphragm size	Medium pressure [bar]	Tightening torque (Static) EPDM/FKM [Nm]	Tightening torque (Static) PTFE [Nm]
8	10	0.6	1.1
15	10	0.8	1.7
20	10	0.9	3.0
25	10	1.2	3.5
32	10	2.5	4.0
40	10	4.5	7.0
50	10	6.0	11.0
65	10	8.0	23.0
80	10	12.0	21.0
100	6	11.0	22.0

(A tolerance of +10% applies to the tightening torques.)

Explosion Protection (ATEX / IECEx)

DANGER

Explosion risk due to electrostatic charge! If statically charged devices or persons discharge suddenly, there is an explosion risk in the potentially explosive area.

• Take appropriate measures to ensure that no electrostatic charge can build up in the potentially explosive area.
• Only clean the device surface by wiping it gently with a damp or anti-static cloth.
• Ground the actuator and the valve body.

Device Grounding:

1. Ground the valve body: To establish potential equalization, ground the valve body to the piping system using a conductive connection.
2. Exposed metal parts not integrated into the valve potential equalization (PA) must be incorporated into the PA by the customer via an additional PA connection.
3. Ground conductive parts: Conductive parts must be grounded separately. Install a grounding strap clip or grounding terminal and ground via a grounding point.