BURKERT 20109570 (Type 2933) is a 2/2-way manually operated diaphragm valve designed for shut-off control in sanitary, sterile, and processing applications. The valve incorporates a stainless steel tube valve body (VP) made of 1.4435-BN2/UNS S31603 (316L) with G 1/2" internal threaded ports, an autoclavable stainless steel diaphragm bonnet, and a high-temperature EPDM diaphragm (material code AD). The internal flow path delivers a water flow coefficient Kv of 7.0 m³/h (Cv of 8.2 gal/min) with minimal dead space, supporting operating pressures from 0 to 10 bar across temperatures from -10 °C to +143 °C.

The manual actuator features a compact 45 mm diameter handwheel (size S), an integrated optical position indicator with graduated scale, and an adjustable single minimum stroke limiter (closing limiter). The valve is certified for clean-in-place (CIP) and steam-in-place (SIP) processes and complies with FDA 21 CFR, USP Class VI, and European Regulation (EC) 1935/2004 requirements for food, beverage, and pharmaceutical contact.

Technical Specifications

Parameter	Specification
Article number	20109570
Valve Type	Type 2933 (Basic manual actuator)
Valve function	2/2-way shut-off valve
Port connection	G 1/2" internal thread (parallel pipe thread)
Product key connection code	GM84
Diaphragm size	15
Nominal diameter	DN 15 (1/2")
Body construction	Tube valve body (VP)
Body material	Stainless steel pipe 1.4435-BN2 / UNS S31603 (316L)
Diaphragm bonnet material	Stainless steel 1.4308
Handwheel material	Stainless steel (Size S, Ø 45 mm)
Valve spindle material	Stainless steel 1.4305
Diaphragm material	EPDM high-temperature (AD)
Operating medium pressure	0 to 10 bar (static)
Medium temperature range	-10 °C to +143 °C (steam sterilisation: +150 °C for 60 min)
Ambient temperature range	-10 °C to +130 °C (short-term up to +150 °C, autoclavable)
Flow coefficient Kv (water)	7.0 m³/h (Cv = 8.2 gal/min)
Position indicator	Optical indicator with rotation and stroke scale
Stroke limitation	Adjustable minimum stroke limiter (closing limiter)
Product identification	Data matrix code on type label

Materials and Valve Construction

Item No.	Element	Material
1	Handwheel	Stainless steel (optionally 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 (optionally PPS)
5	Diaphragm	High-temperature EPDM (AD), bayonet catch attachment
6	Valve body	Stainless steel tube 1.4435-BN2 / 316L (VP)

The EPDM (AD) elastomer diaphragm withstands steam sterilisation up to +150 °C for 60 minutes. Extending sterilisation intervals is permissible, though service intervals must be adjusted accordingly.

Approvals and Sanitary Conformity

Standard / Conformity	Scope and Details
EC Regulation 1935/2004	Materials suitable for food and beverage contact according to European declaration.
FDA 21 CFR	EPDM compound formulation complies with US Food and Drug Administration requirements.
USP Class VI	In-vivo biological reactivity testing passed according to USP Class VI standards.
CE Conformity	Complies with applicable European Union directives and harmonised standards.

Dimensions

Manual Actuator Dimensions

Diaphragm Size	Handwheel Designation	Handwheel Diameter Ø B [mm]	Open Height H1 [mm]	Closed Height H2 [mm]	Pitch per Rotation [mm]
6	T (Tiny)	35	49	42	1.5
8	T (Tiny)	35	54	49	1.5
15	S (Small)	45	84	78	1.75
20	S (Small)	45	95	86	1.75
25	S (Small)	45	101	90	1.75

Tube Valve Body (VP) with G Internal Thread Dimensions

Diaphragm Size	Port Thread B	L [mm]	A [mm]	h [mm]	H [mm]	Width Across Flats SW [mm]	Product Key
8	G 1/4	85	9	11.70	20.3	17	GM82
15	G 1/2	102	14	14.35	25.0	27	GM84
20	G 3/4	118	12	17.15	30.45	32	GM85
25	G 1	127	14	20.55	37.4	41	GM86
32	G 1 1/4	146	16	25.10	46.3	50	GM87
40	G 1 1/2	159	18	29.35	53.5	60	GM88
50	G 2	191	20	35.35	65.5	70	GM89

Actuator Function and Stroke Limiter

Turning the handwheel counterclockwise lifts the spindle and opens the valve flow path. Turning the handwheel clockwise closes the diaphragm down against the weir of the tube valve body. The optical position indicator exposes a yellow mark with graduated stroke scale as the handwheel opens (30 rotation divisions on Type 2933 size S).

Setting the Minimum Stroke Limit

The minimum stroke limit functions as a mechanical closing limiter to protect the EPDM diaphragm from over-compression:

1. Move the valve to the closed position by turning the handwheel clockwise.
2. Loosen the hexagon socket retaining screw (width across flats 2 mm) on the handwheel and lift off the handwheel.
3. Screw down the hexagon nut until it makes firm contact with the stop.
4. Reinstall the handwheel on the actuator, ensuring the drive square of the spindle and the hexagon head of the nut align with the internal profile of the handwheel.
5. Tighten the handwheel screw to 0.9 Nm.

Operating Precaution

Never screw the hexagon nut onto the drive square of the spindle. The minimum stroke limit may only be set within the 0% to 25% opening stroke range. Tighten the handwheel only until media shut-off is achieved; excessive torque accelerates diaphragm wear.

Operating Pressures and Torques

Tightness criteria are defined as follows:

• Static tightness: Valve is closed, seated against the weir, with up to 10 bar applied on one port side. No leakage occurs across the seat.
• Dynamic tightness: Valve is closed against active line flow until specified torque is reached, sealing against differential process pressure.

Handwheel Closing Torques at 10 bar Medium Pressure

Diaphragm Size	Static Tightness (EPDM/FKM) [Nm]	Static Tightness (PTFE) [Nm]	Dynamic Tightness (EPDM/FKM) [Nm]	Dynamic Tightness (PTFE) [Nm]
8	0.6	1.1	0.9	1.2
15	0.8	1.7	1.5	2.5
20	0.9	3.0	2.0	4.5
25	1.2	3.5	3.6	5.0
32	2.5	4.0	8.0	15.0
40	4.5	7.0	12.0	15.0
50	6.0	11.0	15.0	20.0

A tolerance of +10% applies to all specified tightening torques.

Body Fastening Screw Tightening Torques

Diaphragm Size	Cast / Forged Body (VS, VG) EPDM [Nm]	Cast / Forged Body (VS, VG) PTFE [Nm]	Tube Valve Body (VP) EPDM [Nm]	Tube Valve Body (VP) PTFE [Nm]
8	2.0	2.5	2.0	2.5
15	3.5	4.0	3.5	4.0
20	4.0	4.5	4.0	4.5
25	5.0	6.0	7.0	8.0
32	6.0	8.0	8.0	10.0
40	8.0	10.0	12.0	15.0
50	12.0	15.0	15.0	20.0

Installation and Self-Draining

Installation position is arbitrary, with actuator facing upward preferred. To ensure self-draining in sanitary installations:

• Position the valve at the required inclination angle according to ASME BPE standards.
• Ensure the laser-marked draining angle on the tube valve body points upward.
• Align the diaphragm bonnet so that one of the leak detection relief bores sits at the lowest physical position.

Pre-Installation Check

Depressurise and flush pipeline systems prior to installation. Flush out welding residue, metal shavings, and packing particulate before installing the diaphragm valve.

Maintenance and Diaphragm Replacement

The manual actuator requires no lubrication during normal operation. Inspect the leak detection relief bore periodically. If liquid escapes, replace the diaphragm immediately.

Diaphragm Replacement Steps

1. Depressurise the pipeline and drain remaining media.
2. Rotate the handwheel counterclockwise to the fully open position.
3. Loosen the four body fastening screws crosswise and detach the actuator assembly from the valve body.
4. Rotate the handwheel clockwise to the fully closed position to extend the compressor.
5. Disengage the diaphragm from the compressor bayonet socket by rotating it 90°.
6. Insert the bayonet pin of the replacement EPDM diaphragm into the compressor slot and lock it with a 90° turn.
7. Rotate the handwheel counterclockwise back to the fully open position.
8. Align the diaphragm tab perpendicular (90°) to the pipeline flow direction.
9. Place the actuator assembly back onto the valve body. Tighten screws lightly crosswise, stroke the handwheel twice to seat the elastomer, then reopen by approximately 20%.
10. Torque the four body screws crosswise in three progressive steps (1/3, 2/3, and full torque of 3.5 Nm for size 15 VP body).

Spare Parts and Accessories

Replacement Diaphragms for Diaphragm Size 15

Diaphragm Material	Bürkert Material Code	Article Number	Fastening Mechanism
EPDM (AD)	EPDM E04	693 163	Bayonet catch
FKM (FF)	FKM F01	693 164	Bayonet catch
PTFE / EPDM (EA)	EPDM E04 / PTFE P05	20093069	Bayonet catch
Advanced PTFE / EPDM (EU)	EPDM E04 / PTFE P06	20093079	Bayonet catch
GYLON® / EPDM laminate (ER)	PTFE L08	693 176	Bayonet catch

Actuator Accessories

Accessory Description	Article Number
4-fold nylon locking mechanism with 3 mm bracket	93719475
Inductive proximity switch (initiator) M5	550412
Inductive proximity switch (initiator) M5 ATEX	904779