BURKERT 324651 (Type 2100) is a pneumatically operated 2/2-way angle seat valve engineered for decentralized process automation in demanding industrial fluid systems. Built with a cast CF3M stainless steel body featuring G 2 internal threaded connections (DN50), the valve is powered by a 90 mm (size N) single-acting pneumatic actuator. The valve operates under control function A (normally closed by spring force), utilizing an incoming media flow directed below the valve seat. Media sealing is provided by a virgin PTFE seat seal meeting DIN EN 12266-1 leakage rate A, backed by a self-adjusting PTFE V-ring spindle packing gland with integrated spring compensation. This configuration is rated for operating pressures up to 10.0 bar(g) and fluid temperatures ranging from -10 °C to +185 °C (derated up to +230 °C according to DIN EN 12516-1), delivering a water flow capacity of 55 m³/h ($K_v$). Both Clean-in-Place (CIP) and Steam-in-Place (SIP) sterilization cycles are supported.

Technical Specifications

Parameter	Specification
Article Number	324651
Valve Type Family	Type 2100 ELEMENT
Nominal Diameter	DN 50 (NPS 2)
Port Connection	G 2 internal thread (DIN ISO 228-1)
Circuit Function	2/2-way, Control Function A (normally closed by spring force)
Actuator Size	Ø 90 mm (size N)
Operating Pressure Range	0.00 bar(g) to 10.00 bar(g)
Minimum Pilot Pressure	5.0 bar(g)
Maximum Pilot Pressure	10.0 bar(g)
Flow Coefficient ($K_v$)	55 m³/h (water at +20 °C, 1 bar inlet pressure, free outlet)
Seat Leakage Rate	Leakage rate A according to DIN EN 12266-1
Valve Body Material	Cast stainless steel CF3M (equivalent to 1.4404 / 316L)
Seat Seal Material	PTFE (Polytetrafluoroethylene)
Spindle Packing Gland	Self-adjusting PTFE V-rings with spring compensation
Medium Temperature Range	-10 °C to +185 °C (up to +230 °C with pressure derating)
Permissible Fluid Viscosity	Max. 600 mm²/s
Pilot Air Connection	Push-in connector for 6 mm external hose (G 1/8 option)
Pilot Air Media	Filtered compressed air, neutral gases
Degree of Protection	IP65 / IP67 according to EN 60529, NEMA Type 4X
Cleanability	CIP (Clean-in-Place) and SIP (Steam-in-Place) capable

Materials of Construction

Item	Component	Material
1	Ground terminal	Stainless steel 1.4301 / 1.4305 (ATEX variants only)
2	Optical position indicator	Polysulfone (PSU)
3	Pilot air ports	Polypropylene (PP) push-in connector (standard); G 1/8 stainless steel 1.4305 (option)
4	Actuator cover	Polyphenylene sulfide (PPS)
5	Actuator casing	Stainless steel 1.4561 (316Ti)
6	Piston seal	Fluoroelastomer (FKM)
7	Spring	Stainless steel 1.4310
8	Pipe	Stainless steel 1.4401 (316) / 1.4404 (316L)
9	Packing gland	Filled PTFE V-rings with spring compensation
10	Spindle	Stainless steel 1.4401 (316) / 1.4404 (316L)
11	Spindle guide	Polyether ether ketone (PEEK)
12	Body seal	Graphite (PTFE optional)
13	Swivel plate	Stainless steel 1.4401 (316) / 1.4404 (316L)
14	Seat seal	PTFE (PEEK optional)
15	Valve body	Cast stainless steel CF3M

Lubricant Compliance

Lubricants applied within the spindle packing gland and pneumatic actuator assembly are classified according to NSF H1 for incidental contact with food-processing media.

Operating Principle and Flow Direction

In control function A, the valve is maintained in the closed position by actuator spring force acting downwards on the swivel plate. Compressed pilot air supplied to pilot air port 1 acts on the lower surface of the actuator piston, compressing the internal springs and raising the spindle to open the seat. When pilot air is vented, the springs force the spindle and seat seal back onto the orifice seat.

Article 324651 is engineered specifically for media flow entering below the valve seat (flow to open). Because line pressure acts against the underside of the swivel plate, line pressure assists in opening the valve and prevents the onset of closing water hammer.

Liquid Media Operating Limit

Do not use valves configured with flow above the seat for liquid media. Rapid seat closure against moving liquid columns generates hydraulic pressure surges (water hammer) that can rupture pipework and valve bodies. Flow below the seat (as implemented on 324651) must always be selected for liquid service.

Temperature and Pressure Ratings

While article 324651 features a maximum mechanical pressure rating of 10.0 bar(g) for the DN50 size N actuator configuration, the allowable continuous operating pressure decreases at elevated medium temperatures in compliance with pressure-temperature ratings:

Pressure Derating for CF3M Body according to DIN EN 12516-1 (PN25)

Medium Temperature (°C)	Maximum Permissible Operating Pressure (bar)
-10 to +50	25.0 (limited to 10.0 bar by 324651 actuator/spring balance)
+100	24.5 (limited to 10.0 bar by 324651 actuator/spring balance)
+150	22.4 (limited to 10.0 bar by 324651 actuator/spring balance)
+185	20.8 (limited to 10.0 bar by 324651 actuator/spring balance)
+200	20.3 (limited to 10.0 bar by 324651 actuator/spring balance)
+230	19.0 (limited to 10.0 bar by 324651 actuator/spring balance)

Ambient and Medium Temperature Limits

• Push-in hose connections: Medium temperature -10 °C to +230 °C; ambient temperature -10 °C to +60 °C.
• Threaded pilot port bushings: Medium temperature -10 °C to +230 °C; ambient temperature -10 °C to +100 °C.
• Equipped with control heads (Type 8691 / 8695): Ambient temperature limited to -10 °C to +55 °C.

Dimensions

Actuator Dimensions for DN50 Actuator Size 90 (N)

Actuator Size	Ø A (mm)	B (mm)	H (mm)	K/M (mm)
90 (N)	120	262	261	236

Dimensions B, H, K, and M represent maximum outer envelope values and may be up to 6 mm less depending on process connection tolerances.

Internal Threaded Body Dimensions (G 2 / DN50)

Port Connection	DN	NPS	E (mm)	CM (mm)	LM (mm)	AF (Wrench Flat, mm)
G 2	50	2	24	45	150	70

Installation and Actuator Alignment

The valve may be installed in any physical mounting orientation, though an upright vertical position with the actuator facing upwards is preferred. Align pipeline flanges or threads without mechanical strain prior to final fastening.

Body Connection Tightening Torques

When securing or reinstalling the actuator housing to the stainless steel CF3M valve body, observe the defined torque parameters:

Nominal Diameter (DN)	Actuator Sizes	Tightening Torque (Nm)	Tolerance (Nm)
DN 15	40 (C), 50 (D), 63 (E)	45	+10 / -5
DN 20	40 (C), 50 (D), 63 (E), 80 (F)	50	+10 / -5
DN 25	50 (D), 63 (E), 80 (F)	60	+10 / -5
DN 32	63 (E), 80 (F), 100 (G)	65	+10 / -5
DN 40	63 (E), 80 (F), 100 (G), 125 (H)	65	+10 / -5
DN 50	63 (E), 70 (M), 80 (F), 90 (N), 100 (G), 125 (H)	70	+10 / -5
DN 65	80 (F), 100 (G), 125 (H)	70	+10 / -5
DN 65	175 (K), 225 (L)	100	+10 / -5
DN 80	125 (H), 130 (P)	120	+10 / -5

Actuator 360° Alignment Procedure

Pneumatic pilot ports can be positioned 360° to accommodate tight pipe routing:

1. Clamp the valve body in an appropriate bench-holding fixture.
2. Apply 5.0 bar compressed air to pilot air port 1 to shift the valve into the fully open position. Rotating the actuator while seated can destroy the PTFE seal.
3. Hold the body connection hex flats with an open-end wrench, then place a second wrench on the actuator connection hexagon nut.
4. Rotate the actuator exclusively in the specified clockwise rotational direction shown in the diagram until the pilot ports achieve the desired orientation.

Spring Hazard

The internal actuator chamber contains a heavily pre-compressed spring assembly. Never attempt to disassemble or unbolt the actuator housing.

Maintenance and Troubleshooting

Conduct regular visual inspections of the three primary boundary zones:

Inspection Zone	Observed Condition	Corrective Action
Media connectors (1)	Fluid seepage across pipeline thread joints	Re-seal or torque G 2 pipe connection threads
Relief bore (2)	Process media dripping from actuator weep hole	Replace the spindle packing gland kit or actuator assembly
Valve seat (3)	Downstream leakage while actuator is de-energized	Replace the swivel plate and PTFE seat seal disc

Troubleshooting Guide

Problem	Probable Cause	Corrective Action
Actuator fails to open	Pilot air port reversed or de-pressurized	Connect pilot pressure line (min. 5.0 bar) to pilot air port 1
	Pilot air supply pressure below 5.0 bar(g)	Increase pilot supply pressure to 5.0–10.0 bar(g)
	Media line pressure exceeds 10.0 bar(g)	Reduce pipeline operating pressure to within rated limits
Valve leaks across the seat	Debris entrapped between PTFE seal and seat orifice	Flush line; install upstream strainer with ≤ 1 mm mesh
	Worn or scored PTFE seat seal disk	Replace swivel plate assembly
Leakage at actuator relief bore	Worn V-ring packing gland seals	Replace spindle packing using socket wrench tool 683223

Automation Integration

Type 2100 is engineered for direct mechanical and pneumatic coupling with Burkert ELEMENT automation modules without external pilot tubing:

• Type 8691 / 8695 Control Heads: Provide inductive position sensing, micro-pilot solenoid actuation, colored high-power status LEDs, and digital communication (AS-Interface, IO-Link, or büS).
• Type 8690 / 8697 Pneumatic Control Units: Provide compact mechanical or inductive end-position switches, integrated pilot valve actuation, and optical status indication under IP65/67 ingress protection.