BURKERT 344605 (Type 2000) is an externally piloted 2/2-way pneumatic angle seat valve configured with a cast stainless steel body (CF3M / 316L) and a polyamide (PA) piston actuator of size 50 (D). The valve operates under control function A (normally closed, NC by spring force) with process fluid directed below the valve seat (flow to open). Process pipe integration is implemented via welded ends according to ISO 4200, DIN EN ISO 1127, and DIN 11866 Series B, with an outer pipe diameter of 13.5 mm and a wall thickness of 1.6 mm (port size DN 8, seat orifice DN 15). Rated for liquid and gaseous media, BURKERT 344605 provides a nominal flow factor Kv of 2.5 m³/h, a working pressure span from 0 to 16 bar(g), and a process temperature capability of -10 °C to +185 °C.

The drive assembly transmits spring closure force through a precision ground 1.4401 / 1.4404 stainless steel spindle directly to the CF3M swivel plate. Positive shut-off against the PTFE seat seal achieves Leakage Rate A in accordance with DIN EN 12266-1 with air test media. Spindle sealing is maintained by a self-adjusting packing gland comprising spring-compensated, filled PTFE V-rings and a PTFE wiper. Compressed pilot air enters through an internal G 1/4 thread connection, requiring a minimum pilot pressure of 4.1 bar(g) up to a maximum of 10 bar(g). The PA actuator features an optical position indicator housed under a clear polycarbonate bonnet, an IP67 enclosure rating, and continuous 360° rotational positioning for pilot air line alignment.

Valve Design and Component Materials

BURKERT 344605 features high chemical resistance and mechanical strength throughout its fluidic and pneumatic sections. The flow-optimised angle seat body geometry ensures laminar transition and reduced pressure drop.

Item	Component	Material
1	Transparent bonnet / position indicator	Polycarbonate (PC)
2	Pilot air connection inserts	Stainless steel 1.4305
3	Actuator body	Polyamide (PA)
4	Piston seal	Nitrile butadiene rubber (NBR)
5	Spindle packing gland	Filled PTFE V-rings with stainless steel spring compensation
6	Actuator spring set	Stainless steel 1.4310
7	Guiding tube	Stainless steel CF3M
8	Wiper	Filled PTFE
9	Body gasket	Graphite (PTFE optional)
10	Valve spindle	Stainless steel 1.4401 / 1.4404
11	Retention pin	Stainless steel 1.4401 / 1.4404
12	Seat seal	Polytetrafluoroethylene (PTFE)
13	Valve body	Stainless steel CF3M (equivalent to 316L)
14	Swivel plate	Stainless steel CF3M / 1.4401 / 1.4404

Operating Principle and Flow Direction

BURKERT 344605 uses control function A (CF A). In the unpressurized rest state, internal helical springs force the actuator piston downward, seating the PTFE seal plate tightly against the orifice to close the valve.

Process media enters through port 1 beneath the valve seat and discharges through port 2. The medium pressure acts against the underside of the swivel plate, assisting the opening motion when compressed control air is applied to the lower pilot port (port 10). Because closing occurs against the direction of fluid travel, sudden line shocks and hydraulic water hammer are effectively eliminated in liquid circuits.

Operating Restriction: Flow Direction

Valves configured with flow direction above the seat must not be used for liquid media due to the severe hazard of pipe burst caused by water hammer. BURKERT 344605 is built specifically for flow below the seat, making it fully approved for liquid media as well as gases and steam.

Technical Data and Operating Limits

BURKERT 344605 conforms to European Pressure Equipment Directive 2014/68/EU and Machinery Directive 2006/42/EC. It is suitable for water, alcohols, oils, fuels, hydraulic fluids, saline solutions, lyes, organic solvents, neutral gases, and clean saturated steam.

Specification Parameter	Value
Port connection size	DN 8 (pipe outer diameter 13.5 mm)
Pipe connection standard	ISO 4200 / DIN EN ISO 1127 / DIN 11866 Series B
Pipe dimensions (OD x WS)	13.5 mm x 1.6 mm (inner diameter 10.3 mm)
Orifice seat diameter	DN 15 (15 mm)
Flow factor Kv (water, +20 °C, 1 bar Δp)	2.5 m³/h
Flow factor Cv (US gpm)	2.89 gpm
Nominal pressure rating	PN 25 (DIN EN 1333) / Class 150 (DIN EN 1759)
Operating medium pressure range	0 to 16 bar(g)
Required minimum pilot pressure	4.1 bar(g)
Maximum pilot pressure	10 bar(g)
Pilot control fluid	Filtered air, neutral gases
Process medium temperature range	-10 °C to +185 °C
Permissible ambient temperature	-10 °C to +40 °C (maximum envelope up to +60 °C)
Valve body pressure rating limit	PN 25 (25 bar at -10 to +50 °C; 22.4 bar at 150 °C; 20.3 bar at 200 °C)
Viscosity limit	Maximum 600 mm²/s
Sound pressure level	< 70 dB(A)
Cleaning compatibility	CIP (Clean-in-Place) and SIP (Sterilisation-in-Place) capable

Dimensional Specifications

Dimensional verification is required during piping pre-fabrication and clearance planning. The ISO 4200 welded connection is machined directly into the cast CF3M stainless steel body.

Dimension Code	Component / Section	Dimension Value
LS	Total valve body length (face-to-face weld ends)	100 mm
ES	Welded spigot cylindrical end length	20 mm
CS	Centerline to bottom body clearance	34 mm
∅ DS	Pipe outer diameter	13.5 mm
WS	Pipe wall thickness	1.6 mm
∅ A	Actuator casing outer diameter	64 mm (Size 50 / D)
B / H	Centerline to top of transparent bonnet	145 mm (maximum)
K / M	Centerline to pilot air connection axis	129 mm (maximum)
P	Pilot air thread connection	G 1/4
BS / HS	Overall clearance envelope along diagonal spindle axis	216 mm (maximum)

Installation, Welding, and Actuator Handling

BURKERT 344605 may be mounted in any orientation, although mounting with the actuator pointing upright is recommended to minimize particulate settling in the stem guide.

Installation Mandatory Procedure: Orbital / Manual Welding

Prior to welding the stainless steel valve body into the pipeline, the pneumatic actuator must be completely removed from the body. Welding heat conducted through the metal will destroy internal PTFE packing seals, NBR piston seals, and graphite gaskets if the actuator remains attached.

Removing the Actuator from the Valve Body

1. Disconnect and depressurize process fluid lines and pneumatic feed.
2. Apply 5.0 to 5.5 bar(g) of compressed air to the lower pilot port (marked 10). This lifts the PTFE swivel plate away from the valve seat, preventing mechanical distortion of the sealing contour during unscrewing.
3. Secure the valve body in an appropriate bench vise or pipe clamp fixture.
4. Apply an open-end wrench to the hexagonal flats on the body connection interface (wrench flat size WAF 27 or suitable size). Never use a pipe wrench or grip the plastic actuator body.
5. Unscrew the actuator assembly counterclockwise and withdraw it smoothly from the valve body.

Re-assembling and Torquing the Actuator

1. Inspect the graphite body gasket (Item 9) for scratches or deformation; replace if damaged.
2. Coat the metal mounting threads lightly with food-grade lubricating paste (such as Klüberpaste UH1 96-402).
3. Re-pressurize the lower pilot port with 5.0 bar compressed air to retract the swivel plate.
4. Thread the actuator into the body by hand, then tighten with an open-end wrench to the specified torque of 45 Nm (+10 / -5 Nm).

Stepless 360° Actuator Orientation

The pneumatic pilot ports can be aligned continuously across 360° to facilitate clean hose dressing:

1. Ensure the valve is held open by applying 5.0 bar pilot air to the lower control port.
2. Place an open-end wrench on the lower hex nut of the actuator connection piece and hold the body connection hex stationary with a second wrench.
3. Rotate the upper wrench strictly in the direction shown in the technical drawing until the pilot port reaches the target angle. Do not rotate in the reverse direction to avoid loosening the body interface.

Maintenance, Inspection, and Troubleshooting

The PA piston actuator operates maintenance-free under normal operating conditions. Regular maintenance schedules should focus on external leak detection and dynamic sealing elements.

Inspection Point	Observed Fault	Corrective Action
Media Connection (1)	Leakage at pipeline weld	Re-weld or re-align connecting piping
Relief / Overflow Bore (2)	Media weeping through spindle guide hole	PTFE packing gland worn; replace packing set or actuator
Valve Seat / Swivel Plate (3)	Internal seat passage bypass	Foreign particulate or worn PTFE seal; replace valve seat disc set
Body Joint Gasket	Fluid escaping between body and actuator	Replace graphite body gasket and retorque to 45 Nm

Troubleshooting Guide

Operational Malfunction	Potential Cause	Solution
Actuator fails to open	Pilot air connected to wrong port	Connect pilot supply to lower port (port 10) for CF A
	Insufficient pilot pressure	Raise pilot air supply to at least 4.1 bar(g) (max 10 bar(g))
	Excessive working line pressure	Verify process line pressure does not exceed 16 bar(g)
	Reverse process flow direction	Verify flow enters below the seat according to arrow markings
Seat passes fluid when closed	Debris trapped in valve seat orifice	Flush piping; install an upstream strainer with mesh ≤ 1 mm
	PTFE seat seal worn or gouged	Install replacement swivel plate kit (spare parts kit)
Continuous leakage from relief bore	Packing gland V-rings worn	Replace spindle packing gland seal set using special assembly sleeve

Original Spare Parts and Accessories

Genuine replacement valve seat sets (comprising seal holder, PTFE seat seal, centering nut, and replacement graphite gasket) and complete packing gland maintenance kits are available through Bürkert distribution networks. To ensure operational safety and pressure compliance, use only original manufacturer components.