Burkert 20106862 Type 2934 manually operated diaphragm valve consists of a manually operated actuator, a PTFE/EPDM diaphragm, and a T-valve body. The manual actuator with a PPS (Polyphenylene sulphide) handwheel is available with a PPS diaphragm bonnet and ensures use in hygienic or aggressive ambient conditions. The flow-optimised stainless steel block 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 and a single min-stroke limiter (closing limiter).

Approvals and Conformities

The Type 2934 diaphragm valve is designed to meet stringent hygienic and safety requirements:

• Foods and Beverages/Hygiene: FDA-compliant, USP Class VI-compliant, and suitable for use with food and beverages according to EC Regulation 1935/2004.
• Explosion Protection (ATEX/IECEx): As a category 2 device, suitable for Zone 1/21 and Zone 2/22 (valid for variable code PX51). Maximum surface temperature and ambient limits apply based on the temperature class (T4...T2).

Explosion Hazard in Potentially Explosive Areas

When using the device in potentially explosive areas, ensure proper grounding of the actuator and valve body to prevent electrostatic charging. Only use media with appropriate conductivity limits as specified in IEC 60079-32-1.

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	Polyphenylene sulphide (PPS)
5	Diaphragm	PTFE with EPDM backing membrane
6	Valve body	Stainless steel block material 1.4435 (DIN EN 10088) / 316L (ASTM A479/A479M)

Dimensions

T-Body with Welded Connection

Note: Dimensions in mm, unless otherwise stated. The specific SKU 20106862 features a DN 25 (25.4x1.65) welded connection according to ASME BPE / DIN 11866 Series C.

Performance Specifications

Maximum Permitted Medium Pressure

The values are valid for valve bodies made from stainless steel block material. For the PTFE/EPDM diaphragm (Diaphragm size 20), the maximum permitted medium pressure is 10 bar.

Tightening Torques

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

Diaphragm Size	Maximum Static Operating Pressure	Tightening Torque (PTFE/EPDM)
20	10 bar	3 Nm

Installation

Installation Position of T-Valve Body

The following installation positions are recommended for the installation of the T-valves in circular pipelines to ensure proper self-draining:

Welding Instructions

To prevent damage, dismantle the actuator and diaphragm before welding the valve body into the pipeline. After welding, clean the valve body thoroughly before reassembling the diaphragm and actuator. Tighten the fastening screws crosswise in 3 stages (approx. 1/3, 2/3, and 3/3 of the tightening torque).

Maintenance

When used in accordance with the operating instructions, the actuator of the diaphragm valve is maintenance-free.

• Inspection Intervals: After the first steam sterilisation, or when required, retighten the fastening screws crosswise. After a maximum of 10^5 switching cycles, check the diaphragm for wear. Muddy and abrasive media require correspondingly shorter inspection intervals.
• Diaphragm Replacement: The diaphragm size 20 PTFE/EPDM diaphragm is fastened using a bayonet catch. Loosen the diaphragm by rotating it 90°. Ensure the identification tab is at a 90-degree angle to the flow direction when installing the new diaphragm.