Introduction

Selecting a sampling valve is not simply about choosing a valve size or connection type. The wrong sampling valve can create dead zones, compromise sample representativeness, increase operator exposure and make cleaning nearly impossible. With over 50 years of experience designing sampling solutions for the pharmaceutical, chemical, battery and food industries, FAMAT has identified the key parameters that determine successful powder sampling.

Selecting the wrong sampling valve can compromise your entire process

In powder manufacturing, a laboratory analysis is only as reliable as the sample collected. Even the most sophisticated analytical equipment cannot compensate for a non-representative sample.

Selecting the appropriate sampling valve is therefore much more than choosing a connection size or a valve material. The valve must preserve sample integrity, prevent contamination, ensure operator safety and remain easy to clean throughout its service life.

For more than 50 years, FAMAT has been designing sampling valves for pharmaceutical, chemical, battery, food and specialty chemical applications. During this time, we have identified the key factors that determine successful powder sampling.

This guide explains the most important criteria to consider before selecting a sampling valve.

Why representative sampling matters

The objective of any sampling operation is to collect a sample that accurately reflects the composition of the entire batch.

Poor sampling can lead to:

• Incorrect laboratory results
• Batch rejection
• Process adjustments based on inaccurate data
• Product quality deviations
• Regulatory issues

Even if only a few grams are collected, these grams must represent several hundred kilograms or even several tonnes of powder.

Representative sampling begins with the sampling point but also depends heavily on the sampling valve itself.

Illustration suggestion: Process vessel with correctly installed sampling valve and sampling bottle.

Step 1. Understand your powder

Every powder behaves differently.

Before selecting a valve, evaluate:

Particle size, density and moisture content should also be considered.

Step 2. Evaluate your process conditions

A sampling valve operates under the same conditions as the production equipment.

Questions to answer include:

• Process pressure
• Vacuum level
• Operating temperature
• Cleaning method
• CIP or SIP requirements
• Explosion protection (ATEX)
• Installation orientation
• Available installation space

Ignoring these parameters often results in premature wear or difficult operation.

Step 3. Product Compatibility

The first selection criterion is the product itself.

Aggressive chemicals require corrosion-resistant materials such as Hastelloy C-22 or PTFE-lined components.

Pharmaceutical applications generally use 316L stainless steel because it offers excellent corrosion resistance and supports hygienic manufacturing.

Selecting the wrong material increases the risk of corrosion, contamination and premature equipment failure.

Step 4. Manual or Automated Sampling

Sampling frequency influences valve selection.

Manual valves are suitable for occasional sampling and batch production.

Automated valves provide repeatable sampling during continuous production. They also improve traceability and reduce operator intervention.

Many manufacturers now integrate automated sampling systems with MES or SCADA platforms.

Step 5. Operator Safety

Operator safety remains a priority.

Closed sampling systems reduce exposure to toxic or hazardous materials.

Mechanical safety interlocks, contained bottle connections and closed transfer systems further improve protection.

A safe sampling valve also minimizes environmental emissions and supports EHS compliance.

Step 6. Consider containment requirements

Modern manufacturing increasingly requires operator protection.

Containment should therefore be evaluated from the beginning of the project.

Typical containment options include:

• Standard bottle sampling
• Split Butterfly Valve (SBV)
• Continuous liner
• Isolator integration

Depending on the product toxicity, target exposure levels may range from OEB 1 to OEB 5.

Expanding Piston Technology (EPT®)

FAMAT’s patented Expanding Piston Technology was specifically developed for powder sampling.

Unlike conventional designs, the PTFE sealing element remains outside the product stream during sampling, reducing contamination risks while providing excellent sealing performance.

Key advantages include:

• No elastomer in contact with the product
• Dead-zone-free design
• Excellent cleanability
• High containment compatibility
• Low maintenance
• Long service life

Link to EPT explanation.

Five common mistakes when selecting a sampling valve

Choosing the smallest valve

Small valves may bridge with cohesive powders.

Ignoring powder flow behaviour

Flowability directly affects sampling consistency.

Forgetting cleaning requirements

Cleaning should be considered before installation.

Underestimating containment

Future regulations may require higher containment.

Selecting only on purchase price

A low-cost valve can generate much higher maintenance and cleaning costs.

Real industrial example

A pharmaceutical manufacturer experienced inconsistent laboratory results because powder accumulated inside a conventional sampling valve.

Following an engineering review, the sampling system was replaced with a FAMAT sampling valve using Expanding Piston Technology®.

The new installation eliminated product retention, improved sample repeatability and simplified cleaning procedures while reducing operator exposure.

(Client anonymized.)

How FAMAT helps customers select the right sampling valve

Every application is unique.

Before recommending a solution, FAMAT engineers typically evaluate:

• Powder characteristics
• Vessel design
• Pressure and temperature
• Sampling frequency
• Cleaning procedure
• Containment level
• Regulatory requirements
• Installation constraints

This engineering approach ensures that the selected valve is adapted to the process rather than relying on a standard catalogue selection.

Frequently Asked Questions

Can one sampling valve suit every powder?

No. Powder properties vary significantly and require different valve configurations.

Is DN25 always sufficient?

Not necessarily. Cohesive or sticky powders may require larger bore sizes.

What is representative sampling?

Representative sampling means collecting a sample whose composition accurately reflects the entire process batch.

When is a crust breaker recommended?

When cohesive powders tend to bridge or compact around the valve inlet.

Can sampling valves be integrated into high-containment systems?

Yes. Modern sampling valves can be combined with SBVs, isolators or continuous liner systems depending on the required containment level.

Configure Your Sampling Valve

Every process has unique sampling requirements.

Use the FAMAT Sampling Valve Configurator to configure the valve that best matches your process conditions.

👉 Configure your sampling valve online

FAQ

How do I choose the right sampling valve?

Selecting the right sampling valve depends on product properties, process conditions, containment requirements and cleaning procedures.

Which sampling valve is suitable for powders?

Powder sampling valves should provide representative sampling, easy cleaning and minimal dead volume.

When is high containment required?

High-containment sampling is recommended when handling toxic or highly potent materials such as HPAPIs.

Do sampling valves support CIP and SIP?

Many hygienic sampling valves support both Clean-in-Place (CIP) and Sterilization-in-Place (SIP).

Can one sampling valve handle multiple products?

Yes, provided the valve is properly cleaned and validated between production batches.