BURKERT 20090693 (Type 2961) is a manually operated 2-way globe control valve engineered for continuous flow regulation and shut-off in demanding industrial and hygienic media loops. The unit pairs a PPS (polyphenylene sulphide) manual actuator with an investment cast stainless steel 316L/CF3M globe valve body featuring SMS 3008 welded ends (DN 40, tube dimension 38.0 x 1.2 mm). Operating with fluid flow beneath the seat, the valve utilizes an interchangeable 32 mm stainless steel seat and an equal-percentage parabolic plug to deliver a calibrated flow coefficient ($K_v$) of 17.8 m³/h ($C_v$ 20.7 gal/min) with a theoretical rangeability of 50:1. Tight shut-off is ensured by a virgin PTFE soft seat seal conforming to DIN EN 60534-4 Leakage Class VI.

The self-adjusting packing gland incorporates spring-compensated PTFE V-rings that do not require manual adjustment over the service life of the valve. Visual feedback is provided by a dual-scale position indicator comprising a 50-division rotary dial on the handwheel and an exposed linear stroke scale. BURKERT 20090693 complies with the European Pressure Equipment Directive 2014/68/EU, meets EC 1935/2004 and FDA requirements for food contact, and holds ATEX and IECEx Category 2 non-electrical explosion protection ratings for Zone 1/21 and Zone 2/22 installations.

Technical Specifications

Parameter	Specification
Product Type	Type 2961 Globe Control Valve
Article Number	20090693
Nominal Diameter	DN 40 (NPS 1 1/2)
Port Connection	Welded tube ends to SMS 3008 (38.0 mm OD x 1.2 mm wall)
Valve Body Material	Stainless steel 316L / CF3M
Actuator Material	Polyphenylene sulphide (PPS)
Handwheel Diameter	110 mm (Actuator Size M)
Spindle Travel Per Turn	1.75 mm
Nominal Valve Stroke	26 mm
Seat Diameter	32 mm (1 1/4")
Seat Seal Material	PTFE (Polytetrafluoroethylene)
Flow Coefficient ($K_v$)	17.8 m³/h (water at +20 °C according to DIN EN 60534-2-4)
Flow Coefficient ($C_v$)	20.7 gal/min
Flow Characteristic	Equal percentage ($n_g = 50:1$)
Seat Leakage Class	Class VI according to DIN EN 60534-4 (bubble-tight soft seal)
Nominal Pressure Rating	PN 25 (DIN EN 1333) / Class 150 (DIN EN 1759)
Operating Pressure Range	0 bar(g) to 25 bar(g)
Fluid Temperature Range	-10 °C to +130 °C (derating applies at elevated temperatures)
Ambient Temperature Range	-10 °C to +60 °C
Permissible Fluid Viscosity	Max. 600 mm²/s
Spindle Interface	Spindle D14
Stroke Limitation	None (standard base configuration)
Identification Marking	Data matrix code on type label

Conformity and Approvals

BURKERT 20090693 complies with European harmonization legislation and international explosion proof and hygienic standards:

• Pressure Equipment Directive (PED): Evaluated and certified in accordance with Directive 2014/68/EU for fluid groups 1 and 2.
• Food Contact Conformity: All wetted materials comply with Regulation (EC) 1935/2004 of the European Parliament and with the United States Food and Drug Administration (FDA) Code of Federal Regulations according to manufacturer declaration.
• Explosion Protection (ATEX & IECEx, Code PX51): Certified as non-electrical mechanical equipment for Category 2 hazardous environments (Zone 1/21 and Zone 2/22):
  • ATEX Certificate: EPS 18 ATEX 2 008 X, marking II 2G Ex h IIC T4...T2 Gb and II 2D Ex h IIIC T135 °C...T300 °C Db
  • IECEx Certificate: IECEx EPS 18.0007X, marking Ex h IIC T4...T2 Gb and Ex h IIIC T135 °C...T300 °C Db

Hazardous Area Temperature Ratings

Temperature Class	Maximum Permissible Surface Temperature	Ambient Temperature Range	Maximum Permissible Fluid Temperature
T4	+135 °C	-40 °C to +100 °C	+125 °C
T3	+200 °C	-40 °C to +130 °C	+185 °C
T2	+300 °C	-40 °C to +130 °C	+285 °C

INFO

Operating parameters for BURKERT 20090693 with PTFE seat sealing are restricted by standard material properties to -10 °C to +130 °C medium temperature and -10 °C to +60 °C ambient temperature, which remains within the certified ATEX T4 envelope.

Materials and Construction

Item	Component	Material Specification
1	Actuator Cover	Polyamide (PA)
2	Retaining Screw	Stainless steel 1.4301
3	Locking Device (optional)	Stainless steel 1.4305
4	Handwheel	Polyphenylene sulphide (PPS)
5	Visual Position Indicator & Scale	Polyamide (PA)
6	Packing Gland	Filled PTFE V-rings with spring compensation
7	Spindle / Stem	Stainless steel 1.4401 or 1.4404
8	Spindle Guide	Stainless steel 1.4404 (316L), PTFE filled
9	Housing Body Seal	Graphite
10	Control Cone (Plug)	Stainless steel 1.4571 (316Ti)
11	Seat Seal	PTFE (soft seal for Leakage Class VI)
12	Valve Seat & O-Ring	Stainless steel 1.4571 seat, EPDM seal ring
13	Valve Body	Cast stainless steel 316L / CF3M

Dimensions and Actuator Interface

Actuator Dimensions

For pipe sizes DN 32 to DN 50, Type 2961 uses actuator Size M with a 110 mm diameter handwheel.

Nominal Size DN	Nominal Size NPS	Handwheel ∅ (Size)	Overall Height H1 [mm]	Height with Interlock H2 [mm]
15	1/2	45 mm (S)	217	224
20	3/4	45 mm (S)	224	230
25	1	45 mm (S)	228	234
32	1 1/4	110 mm (M)	296	303
40	1 1/2	110 mm (M)	301	307
50	2	110 mm (M)	307	313
65	2 1/2	160 mm (L)	361	368
80	3	160 mm (L)	369	375
100	4	160 mm (L)	379	385

Welded Body Dimensions

BURKERT 20090693 is equipped with SMS 3008 welded ends (outer diameter 38.0 mm, wall thickness 1.2 mm). Related welded body dimensions for the Type 2961 range are detailed below.

DN	Port Type	Insertion Depth ES [mm]	Face-to-Face LS [mm]	Tube ∅ DS [mm]	Wall Thickness WS [mm]
40	SMS 3008	26	150	38.0	1.2
40	DIN EN ISO 1127 / ISO 4200	26	150	48.3	2.0
40	DIN 11850-2 / DIN 11866 series A	26	150	41.0	1.5
40	ASME BPE (NPS 1 1/2)	26	140	38.1	1.65

Fluidic Performance and Operating Limits

The flow profile conforms to DIN EN 60534-2-4 with flow entering beneath the valve plug. The valve retains an equal percentage characteristic down to $K_{vR}$ (the minimum $K_v$ value where characteristic tilt tolerance is maintained), established at 5% of stroke for seat sizes greater than 10 mm.

Flow Rate Across Stroke Profile

$K_v$ flow coefficient progression [m³/h] as a function of valve opening stroke for DN 40 globe control bodies with 110 mm handwheel (Size M):

DN	Seat Size [mm]	Max. Pressure [bar]	Seat Seal	5%	10%	20%	30%	40%	50%	60%	70%	80%	90%	100%	$K_{vs}$ [m³/h]
40	25	25	PTFE (VI)	0.40	0.50	0.75	1.1	1.7	2.6	3.8	5.6	8.0	10.7	13.6	13.6
40	32	25	PTFE (VI)	0.48	0.60	0.85	1.3	2.1	3.2	4.6	6.9	11.0	15.0	20.0	20.0
40	40	25	PTFE (VI)	0.60	0.70	1.1	1.7	2.7	4.0	6.0	9.2	13.8	18.2	23.8	24.0

INFO

Article 20090693 is factory-calibrated for an operating $K_v$ rating of 17.8 m³/h ($C_v$ 20.7 gal/min) with a DN 40 port connection and a 32 mm seat opening, providing a 50:1 control turndown.

Seat Seal Selection Criteria

Requirement	Seat Seal Material	Leakage Class (DIN EN 60534-4)	Medium Temperature Range	Application Scope
Bubble-tight shut-off	PTFE	Class VI	-40 °C to +130 °C	Liquids, steam, neutral and aggressive chemicals up to 130 °C
High-temperature tight shut-off	PEEK	Class VI	-10 °C to +230 °C	High-temperature steam and thermal fluids above 130 °C
Harsh process durability	Stainless steel	Class II	-40 °C to +230 °C	Abrasive or erosive media; 0.5% nominal flow leakage permitted

Pressure and Temperature Derating

Maximum allowable operating pressures decrease with elevated fluid temperatures according to DIN EN 12516-1 (PN 25 rating) and ASME B16.34 (Class 150):

Medium Temperature [°C]	PN 25 Body Derating [bar]	ASME Class 150 Derating [bar]	JIS 10K Derating [bar]
-10 to +38 / +50	25.0	19.0	14.0
+100	24.5	16.2	14.0
+130 / +150	22.4	14.8	13.4
+200	20.3	13.7	12.4
+230	19.0	12.7	11.7

Actuator Function and Position Indication

The manual actuator transmits user torque via a threaded spindle directly to the parabolic control cone. Rotating the handwheel counterclockwise lifts the plug against incoming medium pressure (flow below seat); rotating clockwise seats the valve.

• Stroke Scale and Rotary Dial: Turning the handwheel exposes a stationary linear stroke scale graduated on the central column. The rim of the handwheel is graduated into 50 division marks. Combined reading of the linear stroke index and rotary dial allows reproducible adjustment of flow setpoints.
• Stroke Setting Resolution: With actuator Size M, one complete 360° rotation yields 1.75 mm of linear spindle travel.
• Optional Stroke Limitation: The actuator design accommodates an internal hex adjustment sleeve (width across flats 2). The user can adjust minimum and maximum valve openings to preserve critical flow baselines.
• Optional Interlock: The valve actuator can be locked against unauthorized tampering. Actuator Size M supports 13 locking increments per revolution (every 27° corresponding to 0.13 mm of linear stroke). The locking pin incorporates a 3.8 mm hole accepting a standard padlock.

Installation and Assembly

DANGER

Depressurize pipelines, vent or drain process lines, and ensure zero line pressure before loosening body joints or disassembling actuators. Escaping pressurized or hazardous fluid can cause severe injuries.

Welded Body Installation Procedure

To prevent heat damage to internal PTFE and graphite seals during orbital or manual welding, detach the manual actuator from the valve body before welding:

1. Rotate the handwheel counterclockwise approximately two full turns to lift the plug away from the seat ring.
2. Apply an open-end wrench to the body hex flats and unscrew the manual actuator mechanism.
3. Weld or bond the cast 316L/CF3M valve body into the pipeline according to SMS 3008 pipe geometry.
4. Prior to reassembly, inspect the graphite housing seal and replace if deformed or damaged.

WARNING

Do not use unapproved lubricants. For oxygen or food applications, apply only certified food-grade or oxygen-safe lubricants. Lubricate external body connection threads with Klüberpaste UH1 96-402.

5. Thread the actuator assembly back into the valve body. Tighten to the specified torque value using a calibrated torque wrench.

Actuator Assembly Tightening Torques

Valve Body Nominal Size DN	Tightening Torque [Nm]	Tolerance [Nm]
10 / 15	45	±3
20	50	±3
25	60	±3
32	65	±3
40	65	±3
50	70	±3
65	100	±3
80	120	±5
100	150	±5

Hazardous Area Grounding Requirements (ATEX / IECEx)

When deployed under variable code PX51 in Zone 1/21 or Zone 2/22, the following mechanical explosion protection measures must be implemented:

1. Equipotential Bonding: Connect the valve body electrically to the metallic piping network to prevent electrostatic charge accumulation.
2. Component Grounding: Any metallic parts not inherently integrated into the plant bonding network must be grounded using the grounding strap clip or terminal clamp connected to the designated ground point.
3. Electrostatic Cleaning: Wipe plastic actuator surfaces exclusively with a damp or antistatic cloth to prevent spark discharge.
4. Fluid Conductivity Rules (IEC 60079-32-1): Fluids with conductivity $\le 100\text{ pS/m}$ are permitted only if flow velocities do not exceed 1 m/s or piping systems are actively monitored against dry running. Non-particulate fluids with conductivity between 100 and 1000 pS/m require clean vapor or gas conditions. Media exceeding 1000 pS/m carry no velocity restrictions.

Maintenance and Troubleshooting

Under normal operating conditions with clean process media, the manual actuator is maintenance-free. Conduct an external visual inspection annually. Muddy or abrasive media require shorter inspection intervals.

Troubleshooting Guide

Malfunction	Root Cause	Remedial Action
Seat leakage across closed valve	Particulates or debris trapped between plug and seat	Flush line; install upstream strainer or dirt trap
	PTFE seat seal worn or deformed	Replace the closure member / seat seal kit
	Reverse flow orientation	Reinstall valve ensuring flow arrives below seat (follow flow arrow)
	Operating differential pressure exceeds 25 bar	Verify system operating pressure against type label limits
External leakage at relief bore	Spindle packing gland V-rings worn	Replace spindle packing gland set
Stiff or binding handwheel	Spindle threads contaminated or unlubricated	Clean and re-grease spindle with Klüberpaste UH1 96-402