BURKERT 20112410 (Type 2921) is a manually operated 2/2-way globe valve designed for shutting off neutral and aggressive fluids, gases, and steam. Built with a cast stainless steel 316L (CF3M) valve body and an integrated manual actuator, the valve uses a swivel plate closure member that seals against the fluid stream with flow directed below the valve seat. For this specific article number, the port connection is a DN 25 flange according to DIN EN 1092-1 PN 25, paired with a PEEK soft seat seal and a 45 mm diameter polyphenylene sulphide (PPS) handwheel. The valve delivers a nominal water flow coefficient Kv of 13.0 m³/h (Cv 15.1 gpm) and handles operating pressures from 0 bar(g) up to 25 bar(g).

Flow Direction

The valve seat closes against the medium flow. Installation must direct flow beneath the valve seat (flow to open) as indicated by the cast direction arrow on the valve body.

Technical Specifications

Type 2921 covers port connection sizes from DN 10 to DN 100. The operational limits and fluidic data depend on the port connection size, the handwheel size, and the seat seal material.

Connection Size DN	Connection Size NPS	Handwheel Diameter [mm]	Max. Operating Pressure (PTFE Seal) [bar(g)]	Max. Operating Pressure (PEEK Seal) [bar(g)]	Flow Coefficient Kv [m³/h]
10	3/8	45 (S)	25	25	4.7
15	1/2	45 (S)	25	25	4.7
20	3/4	45 (S)	25	25	8.1
25	1	45 (S)	25	25	13.0
32	1 1/4	45 (S)	25	25	20.0
40	1 1/2	45 (S) / 110 (M)	25	25	31.0
50	2	110 (M)	25 (20)*	23 (20)*	45.0
65	2 1/2	160 (L)	24 (15)*	14	73.0
80	3	160 (L)	16	10	110.0
100	4	160 (L)	10	6	165.0

*Note: Pressures in parentheses apply to compressible fluids of Group 1 (hazardous gases and vapors according to Directive 97/23/EC, Article 3 No. 1.3 letter a first dash). For DN 40, handwheel size S (45 mm) is limited to operating pressures below 16 bar.

General Technical Parameters

• Design: 2/2-way globe valve, on/off shut-off function
• Seat leakage rate: Leakage rate A in accordance with DIN EN 12266-1 (air test medium, PTFE and PEEK seat seals)
• Operating media: Steam, water, neutral gases, alcohols, oils, fuels, hydraulic fluids, salt solutions, alkaline solutions, organic solvents
• Viscosity: Up to 600 mm²/s
• Actuator spindle interface: Spindle D10
• Ambient temperature range: -10 °C to +60 °C
• Medium temperature range: -10 °C to +185 °C (PEEK seal); down to -40 °C with low-temperature variant; up to +230 °C with high-temperature variant
• Mounting position: Any position, preferably with actuator upright

Materials of Construction

The internal assembly of Type 2921 utilizes corrosion-resistant metals and engineered polymers to maintain spindle tightness under high switching duty cycles.

Item No.	Component	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	Filled PTFE V-rings, spring-compensated
7	Spindle	Stainless steel 1.4401 (316) / 1.4404 (316L)
8	Spindle guide	PEEK (DN 15 to DN 50); Stainless steel 1.4401/1.4404 (DN 65 to DN 100)
9	Housing seal	Graphite
10	Swivel plate	Stainless steel 1.4401 (316) / 1.4404 (316L)
11	Seat seal	PEEK (standard on 20112410) or PTFE
12	Valve seat with O-ring	Stainless steel 1.4571, EPDM
13	Valve body	Stainless steel 316L / CF3M

Dimensions

Actuator Dimensions

The manual actuator is sized to balance torque requirements across port sizes. Size S (45 mm) features a thread pitch slope of 1.25 mm per revolution.

Nominal Diameter DN	Nominal Diameter 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	45 (S)	296	303
40	1 1/2	45 (S) / 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

Flanged Body Dimensions

Article 20112410 features DIN EN 1092 PN 25 flange dimensions with face-to-face length according to DIN EN 558-1 Series 1.

DN	DIN EN 1092 PN 25 FTF 1 (DIN EN 558-1) ∅DF [mm]	LF [mm]	∅BF [mm]	AF [mm]	∅D [mm]	Holes A x α	∅MF [mm]	JIS 10K FTF 10 (DIN EN 558-2) ∅DF [mm]	LF [mm]	∅BF [mm]	AF [mm]	∅D [mm]	Holes A x α	∅MF [mm]
10	90	130	60	16	14	4 x 90°	13.6	—	—	—	—	—	—	—
15	95	130	65	16	14	4 x 90°	18.1	95	108	70	12	15	4 x 90°	18.1
20	105	150	75	18	14	4 x 90°	23.7	100	117	75	14	15	4 x 90°	23.7
25	115	160	85	18	14	4 x 90°	29.7	125	127	90	14	19	4 x 90°	29.7
32	140	180	100	18	18	4 x 90°	38.4	135	140	100	16	19	4 x 90°	38.4
40	150	200	110	18	18	4 x 90°	44.3	140	165	105	16	19	4 x 90°	44.3
50	165	230	125	20	18	4 x 90°	56.3	155	203	120	16	19	4 x 90°	56.3
65	185	290	145	22	18	8 x 45°	66.0	175	216	140	18	19	4 x 90°	71.5
80	200	310	160	24	18	8 x 45°	81.0	185	241	150	18	19	8 x 45°	84.3
100	235	350	190	24	22	8 x 45°	100.0	210	292	175	18	19	8 x 45°	109.1

For systems designed to American standards, Type 2921 is also available with ANSI B16.5 Class 150 flanges (FTF 37 according to DIN EN 558-2):

NPS	Flange ∅DF [mm]	Face-to-Face LF [mm]	Bolt Circle ∅BF [mm]	Flange Thickness AF [mm]	Bolt Hole ∅D [mm]	Holes A x α	Raised Face ∅MF [mm]
1/2	89	184	60.5	11.2	15.7	4 x 90°	15.7
3/4	99	184	69.9	12.7	15.7	4 x 90°	20.8
1	108	184	79.2	14.2	15.7	4 x 90°	26.7
1 1/2	127	222	98.6	17.5	15.7	4 x 90°	40.9
2	152	254	120.7	19.1	19.1	4 x 90°	52.6
2 1/2	178	276	139.7	22.3	19.1	4 x 90°	62.7
3	190	298	152.5	23.9	19.1	4 x 90°	78.0
4	229	352	190.5	23.9	19.1	8 x 45°	102.4

Other Connection Formats

Beyond flanged bodies, the Type 2921 family includes threaded connections (G, NPT, Rc per EN ISO 228-1, ASME B1.20.1, ISO 7-1), welded connections (EN ISO 1127/ISO 4200, DIN 11850-2, ASME BPE, SMS 3008), and clamp connections (DIN 32676 Series A/B, ASME BPE).

Operating Limits and Pressure Derating

Maximum allowable working pressures decrease at elevated operating temperatures in accordance with the pressure rating standards.

Pressure Derating by Standard

Temperature [°C]	DIN EN 12516-1 (PN 25) Max. Pressure [bar]	ASME B16.34 Cl. 150 Max. Pressure [bar]	JIS B 2220 10K Max. Pressure [bar]
-10 to +38 / +50	25.0	19.0 (at -29...+38 °C) / 18.4 (50 °C)	14.0
100	24.5	16.2	14.0
150	22.4	14.8	13.4
200	20.3	13.7	12.4
230	19.0	12.7	11.7

Application Variant Limits

• High-temperature variant: Adapted packing gland allows operation with steam, neutral gases, and thermal heat transfer media up to +230 °C.
• Water variant: Special packing gland arrangement increases service life in water applications up to +200 °C.
• Drinking water variant: Complies with UBA assessment principles (TrinkwasserV) for hot water up to +85 °C.
• Low-temperature variant: Formulated for media temperatures down to -40 °C.

Actuator Features and Stroke Adjustment

• Position indicator: When the valve opens (turning the handwheel anticlockwise), a yellow optical indicator rises into view.
• Handwheel locking: Size S handwheels can lock in 12 positions per turn (every 30° of rotation corresponds to 0.10 mm of stroke). The locking pin features a 3.8 mm bore to accept a padlock against unauthorized manipulation.
• Stroke limitation: Setting minimum and maximum stroke limits prevents overtravel or maintains minimum bypass flow.

Setting the Stroke Limitation

1. Move the valve to the closed position by rotating the handwheel clockwise.
2. Loosen the screw on the handwheel (AF 2 hexagon socket) and remove the handwheel.
3. Screw the adjustment sleeve clockwise until it stops to set the minimum stroke.
4. Re-mount the handwheel, aligning the spindle square and sleeve hexagon.
5. Rotate the valve to the desired maximum open position.
6. Remove the handwheel again, pull the adjustment sleeve upward, and rotate anticlockwise until it reaches its stop to fix the maximum stroke.
7. Re-mount the handwheel and tighten the fastening screw to a torque of 0.9 Nm.

Installation and Assembly

Pressure Hazard

Depressurize pipelines and drain or vent all process fluids before installing, removing, or servicing the valve. Wear protective gloves when handling valves that operate with hot or corrosive media.

Body Connection Torque

When servicing or installing actuators on valve bodies, adhere strictly to the body connection tightening torques. Grease external body threads with Klüberpaste UH1 96-402 (or equivalent certified lubricant).

Valve Body Nominal Diameter 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

High Vibration and High Temperature Notice

In installations subject to severe vibration or operating temperatures above 140 °C, check the body connection screw joint before startup and at periodic operational intervals.

Maintenance and Troubleshooting

Under normal service conditions, the manual actuator is maintenance-free. Conduct a visual inspection of the valve and check the actuator relief bore for fluid leakage at least once per year. Abrasive or particulate-laden media require shorter inspection intervals.

Fault / Malfunction	Cause	Corrective Action
Valve does not seal tightly at seat	Particulates lodged between seal and seat	Install an upstream strainer / dirt trap
	Seat seal worn or damaged	Replace the closure member / seal set
	Flow direction reversed	Correct piping so flow enters below the seat
	Operating pressure exceeds limit	Verify system pressure against type label limits
Leakage at relief bore	Spindle packing gland worn	Replace the packing gland set

Approvals, Conformity and Ordering Information

• Pressure Equipment Directive: 2014/68/EU
• Drinking water compliance: Materials meet UBA TrinkwasserV evaluation principles (PF39) up to 85 °C.
• Hygiene & food contact: Conforms to FDA 21 CFR (PL02/PL03), USP Class VI biocompatibility (PL04), EC Regulation 1935/2004 (PL01/PL02), and China Food GB standards (PL10).
• Explosion protection (optional code PX51): EPS 18 ATEX 2 008 X / IECEx EPS 18.0007 X, II 2G Ex h IIC T4...T2 Gb, II 2D Ex h IIIC T135 °C...T300 °C Db. Requires grounding of the valve body and actuator.
• Padlock accessory: 4-fold nylon lock with 3 mm shackle, Article no. 93719475.