Burkert Type 2961 control valve consists of a manual actuator and a globe valve body with exchangeable seats made of high-quality stainless steel. Each globe valve body can be equipped with up to 8 valve seat sizes and reaches the desired flow characteristic curve in interaction with parabolic cones. The precise spindle guide enables control, even under demanding operating conditions. A soft PTFE or PEEK seal guarantees reliable sealing. The actuator is made of high-quality plastic (PPS) and is suitable for use in demanding environments. It possesses a visual position indicator and can be optionally equipped with stroke limitation and locking. The packing gland uses tried-and-tested V-seals and possesses spring compensation, which means that it does not need to be pulled back manually.

Product Features

• Excellent control accuracy: Precise spindle guide for demanding operating conditions.
• Exchangeable valve seats: Enable perfect coordination under the most demanding operating conditions.
• Robust actuator: Made of high-quality plastic with optional stroke limitation and locking.
• Versatile connections: Stainless steel valve body available with flange, threaded, clamp, or welded connections.

General Technical Data

Product properties	Description
Design	Globe control valve
Nominal diameter	DN 10...DN 100, NPS 3/8...NPS 4
Flow direction	Flow to open (below seat)
Operating pressure	0 bar(g)...25 bar(g)
Nominal pressure	PN 25 (DIN EN 1333), Class 150 (DIN EN 1759)
Seat leakage	Leakage class II (metal), Leakage class VI for PTFE and PEEK (according to DIN EN 60534-4:2006)
Operating characteristic	Equal percentage
Operating medium	Steam, water, neutral gases, alcohols, oils, fuels, hydraulic fluids, salt solutions, alkalis, organic solvents
Medium temperature	-40 °C...+ 230 °C
Viscosity	Max. 600 mm²/s
Ambient temperature	-10 °C...+ 60 °C
Installation position	As required, preferably with actuator upright

Materials

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 (optional)	PTFE or PEEK
12	Valve seat with O-ring	Stainless steel 1.4571, EPDM
13	Valve body	Stainless steel 316L/CF3M

Approvals and Conformities

• Explosion protection: Optional ATEX / IECEx approval as a category 2 device suitable for zone 1/21 and zone 2/22 (Ex h IIC T4...T2 Gb / Ex h IIIC T135 °C...T300 °C Db).
• Drinking water: Suitable for use in drinking water applications. The materials comply with the assessment principles (UBA) for materials in contact with drinking water.
• Foods and beverages/Hygiene: All wetted materials are compliant with FDA, USP, EC Regulation 1935/2004, and China food GB Standards according to the manufacturer's declaration.

Dimensions

Actuator

Note: Dimensions in mm, unless otherwise stated.

Nominal connection size [DN]	Nominal connection size [NPS]	Handwheel diameter ∅ [mm]	H1	H2 (locking)
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	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

Operating Limits

Operating limits for seat seal

Tight sealing required	Leakage class (DIN EN 60534-4)	Medium temperature	Seat seal
No	II (metal seals)	-40 °C...+230 °C	Stainless steel
Yes	VI (soft seals)	-40 °C...+130 °C (recommended for ≤ +130 °C)	PTFE
Yes	VI (soft seals)	-10 °C...+230 °C (recommended for > +130 °C)	PEEK

Pressure and temperature restriction (derating) of the valve body

Derating the operating pressure as per DIN EN 12516-1/PN25:

Temperature [°C]	Operating pressure [bar]
-10...+50	25
100	24.5
150	22.4
200	20.3
230	19

Function and Operation

By manually overriding the handwheel, the force is transmitted via a spindle and the valve is opened or closed. Turning the handwheel anticlockwise opens the valve, turning it clockwise closes it.

Position Indicator

When turning the handwheel anticlockwise, the reproducible stroke scale becomes visible between the position indicator and the handwheel.

INFO

The scale on the handwheel determines the rotation position of the handwheel (50 positions). The reproducible stroke scale shows, depending on the bottom edge of the handwheel, the relative position of the valve (valve opening) and acts as a fixation point for determining the rotation position.

Flow Direction

The valve seat is always closed against the medium flow. The flow direction should therefore be set such that the valve reaches the flow beneath the valve seat.

Installation and Safety

Risk of injury due to high pressure and escaping medium

Switch off the pressure before working on the device or system. Vent or drain the lines.

Risk of crushing by mechanically powered parts

The upwards and downwards movement of the device means there is a risk of crushing. Do not reach into the openings of the valve body.

Notes for correct installation

• Note the installation position. The device can be installed in any manner, preferably with the actuator facing upwards.
• Ensure pipelines are aligned before connection.
• Note the flow direction. The flow direction is visible on the valve body and on the type label.
• Clear impurities from pipelines (seal material, metal chips, etc.).

Set Stroke Limit (Optional)

Setting the minimum and maximum stroke limit is possible as an option. An adjusting sleeve is used for this purpose.

Lock Handwheel (Optional)

It is also an option to lock the handwheel to prevent unintentional or unauthorised operation of the valve.

The locking pin has a bore (Ø 3.8) and can be secured against unauthorised use with a padlock.