BURKERT 20112527 (Type 2960) is a manually operated 2-way angle seat control valve engineered for fine fluid throttling and continuous flow adjustment across liquid, gas, and steam installations. Constructed with a 316L/CF3M stainless steel cast body and DIN EN ISO 1127 / ISO 4200 / DIN 11866 series B butt-weld ends (outer diameter 21.3 mm, wall thickness 1.6 mm), this DN 15 (NPS 1/2) valve integrates a precision-contoured parabolic plug that delivers up to 35% higher flow throughput than standard globe control valves of equivalent nominal size.

The valve incorporates an equal-percentage flow profile with a 50:1 theoretical rangeability, operating with fluid entering beneath the seat to ensure smooth opening characteristics and stable seating. Sealing integrity is established by a soft PTFE seat seal providing bubble-tight shutoff conforming to DIN EN 60534-4 Leakage Class VI across operating pressures up to 25 bar(g). The manual assembly features a high-grade polyphenylene sulfide (PPS) handwheel (size S, 45 mm diameter) with an integrated optical indicator and calibrated stroke scale, paired with a spring-loaded PTFE V-ring stem packing gland that requires no manual retightening.

Technical Specifications

Specification Parameter	Value
Valve Type	Manually operated 2-way angle seat control valve (Type 2960)
Article Number	20112527
Nominal Diameter	DN 15 (NPS 1/2)
Pipe Connection Standard	DIN EN ISO 1127 / ISO 4200 / DIN 11866 series B
Pipe Dimensions (Ø DS x WS)	21.3 mm x 1.6 mm
Face-to-Face Dimension (LS)	100 mm
Nominal Pressure Class	PN 25 (DIN EN 1333), Class 150 (DIN EN 1759)
Operating Pressure Range	0 bar(g) to 25 bar(g)
Medium Temperature Range	-10 °C to +130 °C (PTFE seat seal limit)
Ambient Temperature Range	-10 °C to +60 °C
Flow Capacity (Kvs / Cv)	5.0 m³/h / 5.8 gpm (measured with water per DIN EN 60534-2-4)
Seat Diameter	15 mm (9/16")
Nominal Full Stroke	14 mm
Flow Characteristic	Modified equal percentage (50:1 rangeability)
Leakage Class	DIN EN 60534-4 Class VI (PTFE soft seal)
Flow Direction	Below seat (flow to open)
Viscosity Handling	Up to 600 mm²/s
Conformities & Standards	Directive 2014/68/EU (PED), EC Regulation 1935/2004, FDA compliant wetted materials

Material Specifications & Component Design

Item No.	Component	Material
1	Cover	Polyamide (PA)
2	Fastening screw	Stainless steel 1.4301
3	Lock pin (optional accessory)	Stainless steel 1.4305
4	Handwheel	Polyphenylene sulfide (PPS)
5	Optical position indicator with scale	Polyamide (PA)
6	Stem packing gland	Filled PTFE V-rings with internal spring compensation
7	Spindle	Stainless steel 1.4401 / 1.4404
8	Spindle guide	Stainless steel 1.4404 (316L), PTFE filled
9	Body gasket	Graphite
10	Control cone	Stainless steel 1.4571
11	Seat seal	PTFE (Polytetrafluoroethylene)
12	Valve body	Cast stainless steel 316L / CF3M

Fluidic Data & Flow Characteristics

Type 2960 valves utilize an equal percentage parabolic control plug that delivers a modified equal percentage characteristic according to DIN EN 60534-2-4. The theoretical rangeability (Kvs / Kvo) is 50:1 for seat diameters from 8 mm to 100 mm. For seat sizes greater than 10 mm, the minimum controllable flow value (Kvr) is maintained at 5% of valve travel.

Flow enters beneath the seat, stabilizing the plug and eliminating water hammer during closing. The table below details the step-by-step flow capacity (Kv values in m³/h) across stroke percentages for DN 15:

Nominal Size	Handwheel Ø	Max Operating Pressure (Leakage Class)	Kv at 5% Travel	Kv at 10%	Kv at 20%	Kv at 30%	Kv at 40%	Kv at 50%	Kv at 60%	Kv at 70%	Kv at 80%	Kv at 90%	Full Kvs
DN 15 (Standard)	45 mm (S)	25 bar(g) (Class VI)	0.16	0.17	0.22	0.40	1.20	2.70	3.50	4.00	4.50	4.80	5.00 m³/h
DN 15 (ASME BPE)	45 mm (S)	25 bar(g) (Class VI)	0.22	0.24	0.30	0.56	1.20	1.50	1.50	1.50	1.50	1.50	1.50 m³/h

Operating Limits & Pressure-Temperature Derating

Maximum allowable working pressure decreases with increasing fluid temperature. The table below outlines pressure limitations according to DIN EN 12516-1 (PN 25) and ASME B16.34 (Class 150):

Operating Temperature	PN 25 Body Rating (DIN EN 12516-1)	Class 150 Body Rating (ASME B16.34)	JIS 10K Rating (JIS B 2220)
-10 °C to +50 °C	25.0 bar	19.0 bar (from -29 °C)	14.0 bar
+100 °C	24.5 bar	16.2 bar	14.0 bar
+130 °C (Max for PTFE seat)	23.2 bar	15.3 bar	13.6 bar
+150 °C	22.4 bar	14.8 bar	13.4 bar
+200 °C	20.3 bar	13.7 bar	12.4 bar
+230 °C	19.0 bar	12.7 bar	11.7 bar

Operating Temperature Restrictions

Article 20112527 is fitted with a soft PTFE seat seal rated for medium temperatures between -10 °C and +130 °C. For processes exceeding +130 °C (up to +230 °C), factory variants equipped with PEEK or stainless steel seats are required.

Dimensional Data

Actuator Dimensions

Pipe Nominal Size (DN / NPS)	Handwheel Diameter (Ø)	Max Width B1 (mm)	Max Height H1 (mm)	Slope per Handwheel Revolution
DN 15 (NPS 1/2)	45 mm (Size S)	148	148	1.25 mm
DN 20 (NPS 3/4)	45 mm (Size S)	154	154	1.25 mm
DN 25 (NPS 1)	45 mm (Size S)	163	163	1.25 mm
DN 32 (NPS 1 1/4)	110 mm (Size M)	224	224	1.75 mm
DN 40 (NPS 1 1/2)	110 mm (Size M)	224	224	1.75 mm
DN 50 (NPS 2)	110 mm (Size M)	241	241	1.75 mm
DN 65 (NPS 2 1/2)	160 mm (Size L)	290	290	2.00 mm

Welded Body Dimensions (DIN EN ISO 1127 / ISO 4200 / DIN 11866 Series B)

Nominal Size (DN)	ES (Weld Depth) [mm]	CS (Center-to-Bottom) [mm]	LS (Face-to-Face) [mm]	Ø DS (Pipe OD) [mm]	WS (Wall Thickness) [mm]
DN 15	19	34	100	21.3	1.6
DN 20	20	39	115	26.9	1.6
DN 25	26	43	130	33.7	2.0
DN 32	26	45	145	42.4	2.0
DN 40	26	49	160	48.3	2.0
DN 50	26	50	175	60.3	2.0
DN 65	26	50	210	76.1	2.3

Operation & Position Indication

Rotating the handwheel counterclockwise lifts the spindle and opens the valve. Turning clockwise drives the plug toward the closed position. For Size S actuators (45 mm handwheel), spindle advance is 1.25 mm per full turn.

• Handwheel Scale: Features 50 perimeter increments to define the rotational angle.
• Stroke Scale: As the handwheel opens counterclockwise, a calibrated linear scale emerges between the lower housing and the wheel rim. Combining the linear height and dial division allows precise, reproducible flow settings.
• Stroke Limiter & Lock (Optional Accessories): Actuators can accept an internal threaded stop sleeve to fix maximum/minimum positions, or a stainless steel locking pin (accepting a 3.8 mm shackle padlock) with 12 locking detents per turn (30° intervals, equivalent to 0.10 mm stroke travel on Size S).

Installation & Maintenance Guidelines

Installation on Welded Pipe Systems

Before welding the valve body into the line, the manual actuator must be separated from the body to protect the seals and internal guide from heat distortion:

1. Turn the handwheel counterclockwise by approximately 2 full rotations to retract the control cone from the valve seat.
2. Engage an open-ended wrench onto the machined body connection flats and unscrew the actuator.
3. Weld the 316L body into the pipe system, ensuring proper line alignment.
4. Prior to reassembly, inspect the graphite gasket (Item 9) and apply approved grease (such as Klüberpaste UH1 96-402) to the body connection male threads.
5. Reassemble the actuator into the body and tighten to the specified torque: 45 Nm ± 3 Nm for DN 15.

Body Connection Tightening Torques

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

Troubleshooting Guide

Malfunction	Underlying Cause	Corrective Action
Valve does not seal tightly	Particulate contamination between plug and seat	Clean seating surface; install an upstream pipeline strainer
	PTFE seat seal worn or damaged	Replace the plug closure member
	Reverse pipeline flow	Reinstall valve matching the flow direction arrow (below seat)
	Line pressure exceeds limit	Verify pipeline pressure against type label limits (max 25 bar)
External leakage at relief bore	Spindle packing gland worn	Replace the PTFE V-ring stem packing set