BURKERT 20087387 (Type 2933) is a manually operated 2/2-way diaphragm valve engineered for sterile, hygienic, and aggressive liquid or gas control. The valve configuration combines a flow-optimised tube valve body (VP) made of forged-equivalent stainless steel pipe 316L / 1.4435 BN2 with an autoclavable manual actuator featuring a polyphenylene sulphide (PPS) diaphragm bonnet and handwheel. Designed with diaphragm size 40 and welded pipe connections according to DIN 11850 Series 2 / DIN 11866 Series A / DIN EN 10357 Series A (53.0 x 1.5 mm, DN 50), it delivers a high water flow coefficient Kv of 46 m³/h while preventing dead zones within process lines.

The manual actuator incorporates a built-in optical position indicator with marked scale graduations, an integrated minimum-stroke closing limiter to prevent diaphragm over-compression, and a compact housing rated for ambient temperatures up to +130 °C (short-term +150 °C). The high-temperature EPDM diaphragm handles medium temperatures from -10 °C to +143 °C and withstands steam sterilisation cycles up to +150 °C for 60 minutes.

Technical Specifications

Parameter	Specification Details
Type	2933 (Basic manually operated diaphragm valve)
Article Number	20087387
Circuit Function	2/2-way shut-off valve
Nominal Diameter (DN)	DN 50 (NPS 2)
Diaphragm Size	40
Flow Rate Kv (Water)	46 m³/h (Cv: 53.6 gal/min)
Operating Pressure Range	0.00 bar to 10.00 bar (PN 10 / Class 150)
Medium Temperature Range	-10 °C to +143 °C (Steam sterilisation: max. +150 °C for 60 min)
Ambient Temperature Range	-10 °C to +130 °C (Short-term up to +150 °C; autoclavable)
Valve Body Type	Tube valve body (VP)
Valve Body Material	Stainless steel pipe 1.4435 BN2 / 316L (UNS S31603)
Port Connection 1 & 2	Welded connection, 53.0 x 1.5 mm
Connection Standards	DIN 11850 R2 / DIN 11866 Series A / DIN EN 10357 Series A
Diaphragm Material	EPDM high-temperature (AD)
Bonnet & Handwheel Material	PPS (Polyphenylene sulphide)
Handwheel Diameter	110 mm (Size M)
Position Feedback Preparation	Without electrical sensors; visual optical position indicator with scale
Stroke Limiter	Integrated single min-stroke limitation (closing limiter)
Cleaning Compatibility	CIP / SIP capable
Product Identification	Laser-etched Data Matrix Code

Material Specifications and Cross Section

All wetted parts comply with strict hygienic processing guidelines. The tube valve body is manufactured from certified high-alloy 316L / 1.4435-BN2 stainless steel tubing according to DIN 11866 / ASTM A269/A270 / DIN EN 10217-7. The EPDM compound AD satisfies FDA 21 CFR 177.2600, USP Class VI, and EC Regulation 1935/2004 requirements.

Item No.	Element	Material Variant
1	Handwheel	Polyphenylene sulphide (PPS) (optional: cast stainless steel 1.4308)
2	Visual position indicator	Polyamide (PA), stainless steel 1.4305
3	Valve spindle	Stainless steel 1.4305
4	Diaphragm bonnet	Polyphenylene sulphide (PPS) (optional: cast stainless steel 1.4308)
5	Diaphragm	EPDM (AD) (optional: PTFE/EPDM EA, advanced PTFE EU, GYLON® ER)
6	Valve body	Stainless steel tube 1.4435 BN2 (VP)

Body Surface Quality

Tube valve bodies (VP) are supplied with an internally electropolished surface of Ra ≤ 0.38 µm (NO17, ASME BPE SF4 / DIN HE4) and externally electropolished surface, or internally and externally glass-bead blasted Ra ≤ 1.6 µm (NO05/NO01).

Dimensions and Actuator Interface

Dimensions for the welded tube valve body (VP) and actuator assembly are detailed below in mm:

Welded Tube Valve Body (VP) Dimensions — DIN 11850 Series 2 / DIN 11866 Series A

Diaphragm Size	Port Connection DN	Outer ∅ D1 [mm]	Wall Thickness s [mm]	Port Length L [mm]	Height h [mm]	Body Height H [mm]	Product Key
8	10	13.0	1.5	90	9.85	16.35	SD40
15	15	19.0	1.5	110	13.20	22.70	SD42
15	20	23.0	1.5	119	15.20	26.70	SD43
20	25	29.0	1.5	129	18.20	32.70	SD44
25	32	35.0	1.5	148	21.20	38.70	SD45
32	40	41.0	1.5	161	24.40	44.90	SD46
40 (Model 20087387)	50	53.0	1.5	192	31.70	58.20	SD47

Manual Actuator Dimensions

Diaphragm Size	Handwheel Size	Height H1 (Open) [mm]	Height H2 (Closed) [mm]	Handwheel Diameter ∅ B [mm]	Slope per Rotation [mm]
6	T	49	42	35	1.5
8	T	54	49	35	1.5
15	S	84	78	45	1.75
20	S	95	86	45	1.75
25	S	101	90	45	1.75
32	M	129	115	110	2.0
40 (Model 20087387)	M	134	116	110	2.0
50	M	149	125	110	2.0
65	H	182	152	272	4.0
80	H	205	163	272	4.0
100	H	207	161	272	4.0

Torques and Tightening Specifications

Applying proper fastening torque prevents external medium leakage while ensuring maximum diaphragm service life. Over-tightening can cause premature diaphragm failure.

Actuator Fastening Screw Tightening Torques

Diaphragm Size	Screws on Forged / Cast / Plastic Body [Nm]	Screws on Tube Body VP (EPDM/FKM) [Nm]	Screws on Tube Body VP (PTFE/GYLON®) [Nm]
8	2.0	2.0	2.5
15	3.5	3.5	4.0
20	4.0	4.0	4.5
25	5.0	7.0	8.0
32	6.0	8.0	10.0
40 (Model 20087387)	8.0	12.0	15.0
50	12.0	15.0	20.0
65	20.0	20.0	30.0
80	30.0	30.0	40.0
100	40.0	—	—

Torque Tolerance

A tolerance of +10% applies to all specified tightening torques. Screws must be torqued crosswise in 3 stages (approx. 1/3, 2/3, and 3/3 of the target torque).

Handwheel Closing Torques for Static and Dynamic Tightness

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 (Model 20087387)	4.5	7.0	12.0	15.0
50	6.0	11.0	15.0	20.0
65	8.0	23.0	28.0	40.0
80	12.0	21.0	50.0	50.0
100	11.0	22.0	52.0	55.0

Installation and Self-Draining Alignment

Type 2933 valves can be installed in any orientation; however, positioning the actuator facing upwards is preferred.

Self-Draining Installation

To guarantee complete self-draining in sanitary installations:

1. Maintain pipeline inclination according to valid ASME BPE guidelines.
2. Align the self-draining angle marking on the port connection of the tube valve body (VP) facing directly upward.
3. Verify the final installation drain angle using a digital protractor.
4. Ensure that one of the leak detection relief bores in the diaphragm bonnet is situated at the lowest point.

Welding Recommendations for Welded Connections

• Rotate the handwheel counterclockwise into the OPEN position before disassembly.
• Loosen the body fastening screws crosswise and detach the actuator and diaphragm prior to welding.
• Support and align the piping to eliminate mechanical stress and vibration on the valve body.
• After welding, clean the tube valve body and verify that internal surfaces are free from weld slag before remounting the diaphragm and actuator.

Operation and Stroke Limiter Setup

Turning the handwheel counterclockwise opens the valve, exposing the yellow visual indicator. The position indicator scale allows reproducible throttle adjustment (30 positions per revolution on Type 2933 Size M handwheels).

Setting the Minimum Stroke Limit (Closing Limiter)

Type 2933 actuators feature an internal hexagon nut under the handwheel cap that functions as a mechanical closing limiter to protect the elastomer diaphragm from excess compression:

1. Turn the handwheel clockwise to close the valve.
2. Loosen the handwheel socket screw (width across flats 2 mm) and remove the handwheel.
3. Screw the hexagon nut down as far as it will go to lock the minimum stroke.
4. Reinstall the handwheel, aligning the spindle square and nut hexagon head, then tighten the handwheel socket screw to 0.9 Nm.

Stroke Limit Restriction

The minimum stroke limit is intended strictly for the 0% to 25% opening stroke range. Never position the hexagon nut within the square section of the spindle.

Maintenance and Diaphragm Replacement

Under normal operating conditions following these instructions, the Type 2933 manual actuator is maintenance-free. Regular inspections of the bonnet relief bore must be conducted to detect medium weeping.

Diaphragm Replacement Procedure for Size 40

1. Relieve line pressure completely and drain all process fluids.
2. Turn the handwheel counterclockwise into the fully OPEN position.
3. Loosen the body screws crosswise and remove the actuator from the valve body.
4. Turn the handwheel clockwise to the CLOSED position to extend the compressor.
5. Unscrew the EPDM diaphragm from the threaded compressor connection.
6. Thread the new replacement EPDM diaphragm hand-tight into the compressor, then back it off by one half-turn counterclockwise to ensure the pin is unstressed.
7. Turn the handwheel counterclockwise to retract the compressor (OPEN position).
8. Align the diaphragm tab at a 90° angle to the fluid flow direction.
9. Place the actuator assembly on the valve body, lightly tighten screws, cycle the valve twice, then open by 20%.
10. Tighten body screws crosswise in 3 stages to the specified 12.0 Nm torque.

Diaphragm Spare Parts Reference

Diaphragm Size	EPDM (AD) Article No.	FKM (FF) Article No.	PTFE/EPDM (EA) Article No.	Advanced PTFE (EU) Article No.	GYLON®/EPDM (ER) Article No.
8	688 421	677 684	20093068	20093078	693 175
15	693 163	693 164	20093069	20093079	693 176
20	693 166	693 167	20093070	20093080	693 177
25	688 424	677 687	20093071	20093082	693 178
32	688 425	677 688	20093072	20093083	693 179
40 (Model 20087387)	688 426	677 689	20093073	20093084	693 180
50	688 427	677 690	20093074	20093087	693 181
65	688 428	677 691	20093075	20093088	586 616
80	688 429	677 692	20093076	20093091	586 617
100	688 430	677 693	20093077	20093092	—

Conformity and Hazardous Area Operation

When ordered with variable code PX51, Type 2933 mechanical valves comply with ATEX and IECEx certifications for Category 2 equipment in Zones 1/21 and 2/22:

• ATEX: EPS 18 ATEX 2 008 X — II 2G Ex h IIC T4…T2 Gb / II 2D Ex h IIIC T135 °C…T300 °C Db
• IECEx: IECEx EPS 18.0007X — Ex h IIC T4…T2 Gb / Ex h IIIC T135 °C…T300 °C Db

Potential Electrostatic Hazards in Ex Zones

When using valves in potentially explosive atmospheres:

• Earth the valve body via conductive connection to the pipeline system.
• Clean surfaces gently using only a damp cloth or antistatic cleaning agent.
• Avoid media velocities exceeding 1 m/s for non-conductive fluids with conductivity ≤ 100 pS/m unless pipe lines are continuously monitored against running dry.