BURKERT 348494 (Type 2031) is an externally controlled 2/2-way diaphragm valve consisting of a pneumatically operated piston actuator, a diaphragm, and a stainless steel valve body. The proven and robust PPS actuator combined with the flow-optimised valve body ensures reliable operation in hygienic or aggressive environments. The minimal dead space design enables high volume flow rates and a wide range of possible applications.

This specific model features a 1/2" clamp connection (DN15), a PTFE diaphragm with an EPDM backing membrane, and operates with Control Function I (double-acting). It is designed to handle pressures up to 10 bar and medium temperatures ranging from -10 °C to 130 °C, making it fully CIP and SIP capable.

Product Identification

The type label provides essential information for identifying the valve's specifications and operating limits.

Description of the type label (example)

Technical Data

Operating Conditions

• Operating medium: Neutral gases and liquids, highly purified, sterile, aggressive or abrasive mediums.
• Control medium: Neutral gases, air.
• Application environment: Indoors and outdoors. Protect the device against electromagnetic interference, UV rays and, when installed outdoors, the effects of climatic conditions.

Permissible Temperatures

Component	Material	Permissible Temperature [°C]
Actuator	PPS	+5...+140
Valve Body	Stainless steel	-10...+140 (short-term up to 150)
Diaphragm	PTFE/EPDM	-10...+130 (Steam sterilisation max. +140 °C for 60 min)

WARNING

The component (actuator, diaphragm, or housing) with the lowest maximum permissible temperature defines the maximum permissible temperature for the medium and environment.

Operating Pressure

Pressure-temperature diagram

INFO

The information in the pressure-temperature diagram is important for material selection. Observe the permissible operating pressure, depending on the medium temperature!

Installation

Ensuring Self-Draining

The installer and the operator are responsible for ensuring self-draining. The following points must be observed for optimum self-draining:

1. Inclination angle of the pipeline: The inclination angle is determined by the installer or operator. For pipelines, the inclination angles specified in the valid ASME BPE standard are recommended.
2. Self-draining angle for valve body: The self-draining angle (α) depends on the size of the valve body (diaphragm size) and the inner diameter of the port connection. The marking for self-draining angles on the port connection serves as a guide and must point upwards.

Installation position for self-draining (β: Inclination angle of the pipeline, α: Self-draining angle)

Compressor Alignment

Risk of crushing

If the compressor is not positioned correctly and the actuator is actuated, this may result in injuries and damage to the device. Before actuating the actuator, ensure that the compressor is in the correct position.

Correct and incorrect position of the compressor

Maintenance and Repair

Inspection Intervals

• After the first steam sterilisation and when required: Tighten the body screws crosswise.
• After 10⁵ switching cycles at the latest: Check the diaphragm for wear.

TIP

Shortened inspection intervals are required for muddy and abrasive media. A bulging PTFE diaphragm may reduce the flow rate.

Replacing the Diaphragm

Risk of injury from sudden discharge of pressure

Disassembling a pressurised device can cause medium to escape unexpectedly or a sudden discharge of pressure. Before disassembly, shut off the pressure and vent all lines. Completely drain the lines.

Tightening Torques for Body Connection (Diaphragm Size 15):

• PTFE Diaphragm: 4 Nm (tolerance: +10%)

When installing the actuator on the valve body, slightly tighten the body screws crosswise without applying pressure until the diaphragm rests between the valve body and actuator. Actuate the valve twice to position the diaphragm correctly. With pressure applied to the upper pilot air port (for CF I), tighten the body screws in three stages (approx. 1/3, then 2/3, and then full tightening torque), in each case crosswise.