The BURKERT 20128871 Type 2921 is a manually operated 2/2-way globe valve designed for reliable on/off control of neutral and aggressive gaseous and liquid media. This specific configuration features a high-quality stainless steel body with a DN 100 welded connection, a PEEK seat seal for high-temperature applications up to 230 °C, and a robust 160 mm PPS handwheel. The tried-and-tested self-adjusting packing gland guarantees optimal tightness and enables low-maintenance operation, even at high switching cycles.

Product Features

• Compact Design: Space-saving construction suitable for demanding environments.
• Long Service Life: Self-adjusting PTFE V-ring packing gland with spring compensation ensures durability.
• Robust Actuator: Made of high-quality Polyphenylene sulphide (PPS) with a visual position indicator.
• High-Performance Seal: PEEK seat seal provides reliable shut-off under challenging operating conditions and high temperatures.

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 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.

Materials

Element	Material
Cover	Polyamide (PA)
Screw	Stainless steel 1.4301
Locking device	Stainless steel 1.4305
Handwheel	Polyphenylene sulphide (PPS)
Visual position indicator	Polyamide (PA)
Packing gland	PTFE V-rings (filled), with spring compensation
Spindle	Stainless steel 1.4401 (316)/1.4404 (316L)
Spindle guide	Stainless steel 1.4401 (316)/1.4404 (316L) (for DN 65...DN 100)
Housing seal	Graphite
Swivel plate	Stainless steel 1.4401 (316)/1.4404 (316L)
Seat seal	PEEK
Valve body	Stainless steel 316L/CF3M

Technical Data

• Operating Medium: Steam, water, neutral gases, alcohols, oils, fuels, hydraulic fluids, salt solutions, alkalis, organic solvents.
• Viscosity: Max. 600 mm²/s.
• Environmental Factors: Protect the device from electromagnetic interference, UV radiation and, when used outdoors, from weather conditions.
• Installation Position: As required, preferably with actuator upright.

Pressure and Temperature Limits

Nominal diameter DN	Maximum permissible pressure PS
DN 100	10 bar (or see type label)

WARNING

In addition to the maximum operating pressures, the operating range of Bürkert process valves is limited by the nominal pressure according to the relevant standard. Observe the derating curves for specific temperature and pressure combinations.

Dimensions

Actuator

Nominal connection size [DN]	Handwheel diameter ∅ [mm]	H1 [mm]	H2 (locking) [mm]
100	160 (L)	379	385

Body with Welded Connection

Nominal diameter DN	ES	LS	EN ISO 1127 1 / ISO 4200 / DIN 11866 series B (∅ DS / WS)	DIN 11850-2 / DIN 11866 series A / DIN EN 10357 series A (∅ DS / WS)
100	26	260	114.3 / 2.6	104 / 2.0

Nominal diameter NPS	ES	LS	ASME BPE / DIN 11866 series C (∅ DS / WS)
4	26	260	101.6 / 2.11

Installation and Operation

DANGER

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.

Installing Valve Body

1. Ensure pipelines are aligned before connection.
2. Note the flow direction visible on the valve body and on the type label.
3. Clear impurities from pipelines (seal material, metal chips, etc.).
4. Weld or bond the valve body in the pipe system.

Lock Handwheel

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

Handwheel size L can be locked in 13 locking positions per revolution (every 27° corresponds to 0.15 mm of stroke). The locking pin has a bore (Ø 3.8) and can be secured against unauthorised use with a padlock.

Servicing and Maintenance

When used in accordance with the operating instructions, the actuator of the manually operated valve is maintenance-free.

• Inspection Intervals: Perform a visual inspection of the device once per year. If leaks occur, replace the respective wearing part. Muddy and abrasive media require correspondingly shorter inspection intervals.
• Cleaning: Use commercially available cleaning agents for external cleaning. Before cleaning, check that the cleaning agents are compatible with body materials and seals.