BURKERT 20064785 (Type 2012) is an externally controlled, pneumatically operated 2/2-way globe valve configured for industrial shut-off applications. The valve assembly comprises a pneumatic piston actuator with a polyamide (PA) housing and an investment cast stainless steel CF3M 2/2-way globe valve body. The process ports are SMS 3008 weld ends designed for DN 100 pipelines, having an outer diameter of 101.6 mm, an inner diameter of 97.6 mm, and a 2.0 mm wall thickness. Control function A operates as normally closed (NC) by internal spring force in the rest position, and flow enters below the seat to provide water-hammer-free operation on liquid and gaseous media.

The self-adjusting spindle packing gland utilizes spring-compensated, carbon-filled PTFE V-rings to maintain stem tightness across thermal cycles. The replaceable screwed-in valve seat works in conjunction with a PTFE seat seal, achieving leakage rate A in accordance with DIN EN 12266-1 using air as the test medium. The valve provides a nominal water flow coefficient Kv of 155 m³/h and is fully rated for Clean-In-Place (CIP) and Steam-In-Place (SIP) operations within process installations.

Technical Specifications

Parameter	Specification
Product Identification	Article no. 20064785, Type 2012 CLASSIC
Nominal Diameter	DN 100 (NPS 4)
Port Connection Type	Weld end according to SMS 3008
Port Dimensions	Outer Ø 101.6 mm, inner Ø 97.6 mm, wall thickness 2.0 mm
Face-to-Face Dimension (LS)	260 mm (weld depth ES = 26 mm)
Operating Pressure Range	0 to 16 bar(g) (10 bar(g) max. for PED 2014/68/EU compressible fluids Group 1)
Pilot Pressure Range	4.8 to 6 bar(g)
Pilot Connection	G 1/4 internal thread
Flow Direction	Flow below seat (flow to open, closes against medium flow)
Flow Coefficient Kv	155 m³/h (water at +20 °C, 1 bar pressure differential)
Seat Leakage Class	Leakage rate A according to DIN EN 12266-1 (PTFE seat seal, test medium air)
Nominal Pressure Class	PN 25 (DIN EN 1333) / Class 150 (DIN EN 1759)
Medium Temperature Range	-10 °C to +185 °C
Ambient Temperature Range	-10 °C to +50 °C (actuator size 225 mm PA)
Maximum Medium Viscosity	600 mm²/s
Control Medium	Compressed air, neutral gases
Degree of Protection	IP67
Explosion Protection Markings	II 2G Ex h IIC T4...T2 Gb, II 2D Ex h IIIC T135°C...T300°C Db; IECEx EPS 18.0007X
Conformity	Pressure Equipment Directive 2014/68/EU, Machinery Directive 2006/42/EC

Design and Operating Principle

BURKERT Type 2012 utilizes a pneumatically actuated piston to translate linear motion via a stainless steel spindle to the sealing swivel plate. In control function A, integrated heavy-duty coil springs drive the spindle downward into the rest position, closing the PTFE seal against the stainless steel seat ring. Applying pilot air pressure of at least 4.8 bar(g) through the bottom pilot port (G 1/4) acts beneath the internal piston, lifting the spindle to full stroke.

Because the process fluid enters beneath the valve seat, the medium pressure acts against the underside of the swivel plate. This arrangement assists opening, avoids pressure surges, and prevents the water hammer associated with abrupt closure on liquid media.

Operational Restriction on Flow Direction

Valves configured for flow above the seat create high risk of pipe rupture and equipment damage due to water hammer when controlling liquid media. Flow above the seat must only be used on gaseous media or steam.

Explosion Protection Rating

Under ATEX certificate EPS 18 ATEX 2 008 X and IECEx EPS 18.0007X, non-electrical mechanical valve assemblies comply with category II 2G/D. Temperature classes span T4 (+135 °C surface max, medium up to +125 °C), T3 (+200 °C surface max, medium up to +185 °C), and T2 (+300 °C surface max, medium up to +285 °C). Temperature limits are restricted by the PA actuator body material specifications to +185 °C medium and +50 °C ambient.

Material Specifications

For actuator size 225 mm (L), component materials are engineered for chemical resistance and thermal cycling:

Pos.	Component	Material
1	Transparent visual indicator cover	Polycarbonate (PC)
2	Actuator housing	Polyamide (PA)
3	Piston seal	Nitrile rubber (NBR)
4	Pilot air ports	Stainless steel 1.4305
5	Spindle packing gland	Filled PTFE V-rings, spring-compensated
6	Compression spring	Stainless steel 1.4568
7	Screw	Stainless steel 1.4305
8	Threaded nipple	Stainless steel 1.4404
9	Body seal	Graphite (PTFE optional)
10	Valve spindle	Stainless steel 1.4401
11	Dowel pin	Stainless steel 1.4401
12	Swivel plate	Stainless steel 1.4401
13	Seat seal	PTFE (optional PEEK, NBR, FKM)
14	Screwed seat with O-ring	Stainless steel 1.4571, EPDM O-ring
15	Valve body	Stainless steel CF3M (cast 316L)

Dimensions and Port Connection

The physical envelope of article 20064785 combines the DN 100 globe valve body with the Ø 225 mm (Size L) actuator:

• Actuator outer diameter (Ø A): 261 mm
• Total height without positioner (H): 504 mm
• Overall height clearance for disassembly (HS): 603 mm
• Pilot air connection (P): G 1/4
• Face-to-face body length (LS): 260 mm
• Weld extension length (ES): 26 mm
• Pipe outer diameter (Ø DS): 101.6 mm
• Pipe wall thickness (WS): 2.0 mm
• Pipe inner diameter: 97.6 mm (SMS 3008 standard)

Performance Specifications and Operating Limits

The permissible operating pressure is bounded by the nominal rating of the pipe connections according to DIN EN 12516-1 and ASME B16.34:

Temperature Range	Maximum Operating Pressure PN 25	Maximum Operating Pressure Class 150
-10 °C to +50 °C	25.0 bar	18.4 bar (at 50 °C)
+100 °C	24.5 bar	16.2 bar
+150 °C	22.4 bar	14.8 bar
+185 °C (PA actuator max.)	20.9 bar	14.0 bar
+200 °C (PPS actuator variant)	20.3 bar	13.7 bar
+230 °C (PPS actuator variant)	19.0 bar	12.7 bar

For article 20064785, the maximum allowable differential pressure across the valve seat is 16 bar(g). In installations subject to the European Pressure Equipment Directive 2014/68/EU handling compressible fluids of Group 1 (dangerous gases and vapours pursuant to Article 4, paragraph 1, item c, i, first indent), the maximum operating pressure is legally restricted to 10 bar(g).

Installation and Assembly Guidelines

Prior to welding the body into the line, the pipeline must be cleared of metal chips, weld slag, and sealing residues. The preferred mounting orientation is with the actuator upright; however, any mounting angle is permitted.

Actuator Disassembly Prior to Welding

To protect the PTFE seat seal and spindle guide from thermal degradation during body welding, the actuator must be removed from the body:

1. Clamp the valve body securely in a vice or holding fixture.
2. Apply 6 bar(g) compressed air to the lower control air connection (G 1/4) to hold control function A in the open position. Removing the actuator while unpressurized risks scoring or warping the PTFE seat seal.
3. Fit an open-end wrench across the wrench flats of the body nipple and unscrew the actuator assembly.
4. Weld the valve body into the pipeline.
5. Once the weld joints have cooled completely, replace the graphite body seal, apply Klüberpaste UH1 96-402 grease to the nipple threads, pressurize the actuator to open, and screw the actuator into the body.

The actuator housing can be rotated 360° to orient the pilot air ports. To adjust port direction, pressurize the actuator to open, counterhold the body nipple with an open-end wrench, and rotate the actuator housing clockwise to the required angle.

Modular Accessories and System Integration

Type 2012 valves integrate directly with modular accessories to create automated packages:

• Position Feedback Type 8697: Compact position feedback unit featuring mechanical or inductive limit switches and integrated LED status indicators. Combines with Type 2012 to form the automated on/off valve system CLASSIC Type 8801-GA. Enclosure rating IP65/IP67, with ATEX/IECEx intrinsically safe variants available.
• Pilot Solenoid Valves Type 6014: Direct-acting 3/2-way plunger valve with banjo bolt coupling that mounts directly into the G 1/4 pilot air port, eliminating intermediate piping. Operates from 0 to 7 bar(g) with power consumption of 8 W.
• Stroke Limiters Type 2XXX: Mechanical stroke limiters installed on the top of the actuator body to manually restrict the maximum or minimum flow opening.

Maintenance, Seat Replacement, and Troubleshooting

The actuator assembly is maintenance-free under normal operating conditions. Wetted wearing parts consist of the PTFE seat seal and the screwed-in valve seat ring.

Valve Seat Replacement

1. Relieve process and control pressure completely and drain all lines.
2. Remove the actuator from the valve body while pressurized in the open position (6 bar).
3. Insert the seat removal socket tool into the internal profile of the DN 100 seat ring.
4. Unscrew the worn seat ring and clean the internal body threads with compressed air.
5. Lubricate the replacement seat threads with Klüberpaste UH1 96-402.
6. Hand-thread the new seat assembly into the valve body and torque to 220 Nm (+10 Nm tolerance) using a calibrated torque wrench.

Troubleshooting Guide

Fault Condition	Probable Cause	Corrective Action
Actuator fails to stroke	Pilot air line connected to wrong port	Connect control pressure to lower port for CFA
	Pilot air pressure below 4.8 bar	Increase pilot air pressure to between 4.8 and 6.0 bar
	Medium pressure exceeds 16 bar	Reduce process line pressure to rated specification
Internal seat leakage	Particulate contamination on seat	Clean seat surfaces; install an upstream strainer
	Worn or grooved PTFE seat seal	Replace the seat seal assembly
	Flow direction reversed (flow above seat)	Reorient body to ensure flow enters below seat
External leakage at relief weep hole	Worn spindle packing gland V-rings	Replace the spindle packing gland kit or actuator assembly