BURKERT 20089760 (Type 2961) is a manually operated 2-way globe control valve designed for precise flow control in process applications involving liquids, steam, and gases. Built with a stainless steel 316L (CF3M) valve body and a PPS manual actuator, this valve features a DN 40 (NPS 1 1/2) welded connection compliant with DIN EN ISO 1127, ISO 4200, and DIN 11866 Series B (pipe dimensions 48.3 x 2.0 mm). Media flow is directed below the seat (flow to open), supporting operating pressures from 0 to 25 bar(g).

The control trim comprises an exchangeable 40 mm stainless steel seat combined with an equal percentage parabolic cone providing a 50:1 theoretical rangeability, yielding a maximum water flow coefficient of Kvs 24 m³/h (Cv 27.7 gpm). Tight shut-off is ensured by a soft PTFE seat seal rated to leakage class VI in accordance with DIN EN 60534-4. The manual actuator features a 110 mm PPS handwheel (Size M), an optical stroke position indicator with a scale, and a spring-compensated packing gland utilizing filled PTFE V-rings that requires no manual retightening.

Technical Specifications

Parameter	Specification
Valve Type	Manually operated 2-way globe control valve (Type 2961)
Article Number (SKU)	20089760
Nominal Diameter	DN 40 (NPS 1 1/2)
Port Connection	Welded ends 48.3 x 2.0 mm (DIN EN ISO 1127 / ISO 4200 / DIN 11866 series B)
Body Material	Stainless steel 316L / CF3M
Nominal Seat Diameter	40 mm (1 1/2")
Flow Capacity Kvs	24 m³/h (water per DIN EN 60534-2-4)
Flow Capacity Cv	27.7 gpm
Flow Characteristic	Equal percentage (theoretical rangeability 50:1)
Flow Direction	Flow to open (flow below seat)
Operating Pressure Range	0 bar(g) to 25 bar(g)
Pressure Ratings	PN 25 (DIN EN 1333) / Class 150 (DIN EN 1759)
Seat Leakage Class	Leakage class VI per DIN EN 60534-4 (PTFE soft seal)
Medium Temperature Range	-10 °C to +130 °C
Ambient Temperature Range	-10 °C to +60 °C
Max. Viscosity	600 mm²/s
Handwheel Diameter	110 mm (actuator size M), polyphenylene sulphide (PPS)
Position Indicator	Visual stroke indicator with scale (polyamide PA)
Stroke Limitation	Without
Actuator Interface	Spindle D14
Product Identification	Data matrix code

Materials of Construction

No.	Element	Material
1	Cover	Polyamide (PA)
2	Screw	Stainless steel 1.4301
3	Locking device	Stainless steel 1.4305
4	Handwheel	Polyphenylene sulphide (PPS)
5	Visual position indicator with scale	Polyamide (PA)
6	Packing gland	PTFE V-rings (filled), with spring compensation
7	Stem	Stainless steel 1.4401 or 1.4404
8	Spindle guide	Stainless steel 1.4404 (316L), PTFE filled
9	Housing seal	Graphite
10	Control cone	1.4571 (optionally hardened)
11	Seat seal	PTFE (soft seal)
12	Valve seat with O-ring	Stainless steel 1.4571, EPDM
13	Valve body	Stainless steel 316L / CF3M

Flow Characteristics and Fluidic Data

The flow characteristic complies with DIN EN 60534-2-4. For nominal sizes above DN 10 mm, the KvR value is defined at 5% valve stroke. Theoretical rangeability for seat size 40 mm is 50:1.

Intermediate Kv Values Across Valve Stroke

For DN 40 bodies, Type 2961 accommodates three exchangeable seat sizes: 25 mm, 32 mm, and 40 mm. Model 20089760 is fitted with the 40 mm seat configuration.

Seat Size (mm)	Max. Pressure (bar)	Rangeability	5%	10%	20%	30%	40%	50%	60%	70%	80%	90%	100%	Kvs (m³/h)
25	25 (VI)	50:1	0.40	0.50	0.75	1.1	1.7	2.6	3.8	5.6	8.0	10.7	13.6	13.6
32	25 (VI)	50:1	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 (20089760)	25 (VI)	50:1	0.60	0.70	1.1	1.7	2.7	4.0	6.0	9.2	13.8	18.2	23.8	24.0

Pressure and Temperature Operating Limits

In addition to the maximum operating pressure of 25 bar(g), the operating range is governed by pressure-temperature derating curves for PN 25 according to DIN EN 12516-1 and Class 150 according to ASME B16.34.

Seat Seal Operating Limits

Tight Sealing Required	Leakage Class (DIN EN 60534-4)	Medium Temperature	Seat Seal Material	Application Notes
No	Class II (0.5% nominal flow)	-40 °C to +230 °C	Stainless steel	Metallic seals are impervious under severe process conditions; an additional shut-off valve is recommended.
Yes	Class VI (tight shut-off)	-40 °C to +130 °C	PTFE (Model 20089760)	Recommended for temperatures up to +130 °C. Eliminates the need for an additional shut-off valve.
Yes	Class VI (tight shut-off)	-10 °C to +230 °C	PEEK	Recommended for temperatures above +130 °C. Not recommended under increased erosive wear.

Dimensional Specifications

Actuator Dimensions

Pipe Connection DN	Pipe Connection NPS	Handwheel Diameter ∅ (mm)	Height H1 (mm)	Height H2 with Locking (mm)
15	1/2	45 (S)	217	224
20	3/4	45 (S)	224	230
25	1	45 (S)	228	234
32	1 1/4	110 (M)	296	303
40 (20089760)	1 1/2	110 (M)	301	307
50	2	110 (M)	307	313
65	2 1/2	160 (L)	361	368
80	3	160 (L)	369	375
100	4	160 (L)	379	385

Welded Body Dimensions

Dimensions according to DIN EN ISO 1127 / ISO 4200 / DIN 11866 series B:

Port Connection DN	ES (mm)	LS (mm)	Outside Diameter ∅ DS (mm)	Wall Thickness WS (mm)
10	20	90	17.2	1.6
15	20	90	21.3	1.6
20	20	100	26.9	1.6
25	26	130	33.7	2.0
32	26	140	42.4	2.0
40 (20089760)	26	150	48.3	2.0
50	26	175	60.3	2.0
65	26	210	76.1	2.3
80	26	230	88.9	2.3
100	26	260	114.3	2.6

Actuator Features and Operation

• Visual Position Indicator: Turning the handwheel counterclockwise reveals the reproducible stroke scale between the bonnet attachment and the handwheel. Working alongside the scale on the handwheel, it enables reproducible manual throttling and positioning.
• Interlock Pin (Optional): The valve can be locked against unintended or unauthorized operation by depressing and rotating a securing pin. The pin contains a 3.8 mm hole accepting a lockout padlock.
• Stroke Limitation (Optional): Both the minimum and maximum valve stroke positions can be restricted via an internal adjustment sleeve after removing the handwheel.

Hazardous Area Conformity and Installation (PX51)

BURKERT 20089760 complies with non-electrical mechanical explosion protection standards under certification code PX51, rated as Category 2 equipment suitable for Zone 1/21 and Zone 2/22 atmospheres:

• 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

Temperature Classes in Hazardous Zones

Temperature Class	Maximum Surface Temperature	Permissible Ambient Temperature	Maximum Medium 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

Electrostatic Charging Precautions

• Surfaces must only be wiped gently using a damp or antistatic cloth to prevent electrostatic discharge.
• The valve body must be conductively bonded to the piping system to ensure equipotential bonding.
• Electrically conductive actuator parts must be grounded independently using the provided grounding strap clamp or grounding terminal shown above.
• Operating media conductivity must comply with IEC 60079-32-1: media with conductivity ≤ 100 pS/m require flow velocity ≤ 1 m/s unless specific monitoring prevents dry pipe operation; media between 100 and 1,000 pS/m are restricted to particle-free liquids, steam, or clean gases; media > 1,000 pS/m are unrestricted.
• Only cleaning agents certified for hazardous environments may be used.

Ordering Information and Accessories

Description	Specification	Article No.
Type 2961 Valve	DN 40, Welded 48.3 x 2.0 mm, Seat 40 mm, PTFE seal, 110 mm PPS handwheel	20089760
Standard Lockout Padlock	3 mm shackle nylon lockout for interlock securing pin	93719475