Ultra High Purity High Temperature Low Pressure Manual Diaphragm Valve Configurations Preventing Critical Process Virtual Leaks

Ultra High Purity High Temperature Low Pressure Manual Diaphragm Valve Configurations Preventing Critical Process Virtual Leaks

Product Application and Purpose
The Ultra High Purity (UHP) High Temperature Low Pressure Manual Diaphragm Valve is engineered for critical vacuum and low-pressure vapor lines in semiconductor fabrication. It is specially configured for processes like chemical vapor deposition (CVD) and atomic layer deposition (ALD), where gas delivery lines must be heated to prevent specialty precursors from condensing. This valve provides positive, manual flow isolation while strictly eliminating virtual leaks that can ruin sub-nanometer wafer processing steps.

 

Eliminating Virtual Leaks Through Advanced Engineering
A virtual leak occurs when gas molecules become trapped in microscopic pockets, welds, or threaded spaces inside a fluid system and slowly desorb into the main flow path during low-pressure vacuum cycles. This valve configuration prevents this phenomenon through key engineering attributes:

• Zero-Dead-Volume Architecture: The internal wetted cavity features a specialized, streamlined design that leaves no dead zones or hidden pockets where process molecules can stagnate.
• High-Temperature Material Stability: Equipped with premium alloy diaphragms (such as Hastelloy C-22) and high-temperature polymers, the valve maintains its shape and seal integrity under constant heat, preventing thermal expansion from creating new trapping sites.
• Mirror Electropolished Finish: Wetted internal surfaces are electropolished to a roughness average of less than 5 micro-inches Ra. This topology drastically reduces surface area, ensuring rapid gas molecule desorption during vacuum purge sequences.

 

Installation and Maintenance Guidelines
Unpack the double-sealed valve exclusively within a certified Class 100 cleanroom. Install the component onto the line using orbital butt-weld or VCR face-seal connections, taking care to avoid any manual over-tightening of adjacent components. When configuring lines that use heat jackets, verify that the heating element covers the body evenly without exceeding the valve’s maximum rated temperature threshold. Conduct comprehensive vacuum decay tests and helium mass spectrometer leak checks to confirm baseline integrity prior to executing active process runs.

 

LD SERIES

LOW PRESSURE MANUAL DIAPHRAGM VALVE

Features
Body
*316L VIM-VAR stainless steel body material for ultrahigh-purity applications.
*The inner surface roughness can reach Ra 5 μin, and the flow channel can be completely cleaned.
1.minimizes entrapment areas.
2.facilitates purging.
3.maximizes flow capacity.

Diaphragm
*Hastelloy C-22 or cobalt-based superalloys (UNS R30003) material for strength and corrosion resistance.
*Optimal design for long cycle life.

Seat
*Fully contained PCTFE seat design provides:
1.excellent resistance to swelling and contamination.
2.improved helium leak test performance.
3.minimal particle generation.
4.long cycle life.
*High cleanliness assembly and packaging are suitable for the high-purity semiconductor industry.
*Every product undergoes helium testing before leaving the factory.

Technical Data

Product Size
Dimensions, in millimeters, are for reference only and are subject to change.

Flow Channel Form

Ordering Information

*The above are standard ordering specifications. If you need to order other specifications and models, please contact our sales personnel or agents.