Want your glass system to always maintain optimal airtightness?
The key is often not the number of maintenance interventions, but whether you have grasped the core sealing points and performed the standardized procedures.
Standardized operations not only improve maintenance efficiency but also fundamentally ensure the system's long-term durability and excellent performance.
1. Core principles：
How do valves achieve sealing?
To solve the problem, you must first understand how it works.
Valve structure schematic
The sealing of glass valves depends on two core elements:
1. Physical sealing: Apply a dedicated vacuum grease between the precisely ground contact surfaces of the plug and the socket to fill microscopic gaps.
2. Negative-pressure fastening: By evacuating the top vacuum cup to negative pressure, atmospheric pressure holds the plug tightly “sucked” into the socket, creating a close fit.
Common misconception: Many maintenance procedures only achieve the first point (applying new vacuum grease) and neglect the second point (re-evacuating the vacuum). This is the main reason for continued leakage after maintenance.
2. Standard operating procedures：
How to correctly evacuate the vacuum cup?
After applying new vacuum grease, you must perform the following operations to re-establish negative pressure in the vacuum cup. Please follow the steps strictly according to your system type.
Preparations before operation
• Maintenance completed and the reactor reinstalled.
• Ensure the valves are set to the following initial positions.
1. For the Labsolar-6A system
• Initial valve positions: A valve (sampling), B, E, C1, C2, D valve (system circulation), C3 valve (circulation pressure).
• Procedure：
a、Turn the D valve to the “vacuum” position, then start the vacuum pump.
b、Slowly rotate the following valves in order, 3–5 turns each: D→A→B→E→C3→C2→C1 (for E valve, rotate the small head up and down 180° back and forth, but do not use the vent port).
c、Return the D valve to the system circulation position, then stop the vacuum pump.
d、Observe for at least 30 minutes to confirm the system pressure does not continue to rise.
2. For the μGAS1000 system
• Initial valve positions: B, E, C1, C2, D valve (system circulation), F valve (vacuum).
• Procedure：
a、Turn the D valve to the vacuum position, then start the vacuum pump.
b、Slowly rotate the following valves in order, 3–5 turns each: F→D→C1→C2→E→B (for F valve, rotate the small head right and left 180° back and forth; for E valve, rotate the small head up and down 180° back and forth; do not go over the “vent” port).
c、Return the D valve to the system circulation position, then stop the vacuum pump.
d、Observe for at least 30 minutes to confirm the system pressure does not continue to rise.
3. For the μGAS1001 system
• Initial valve positions: D, C1, C2 valves (system circulation).
• Procedure：
a、Turn the D valve to the vacuum position, then start the vacuum pump.
b、Slowly rotate the following valves in order, 3–5 turns each: D→C1→C2.
c、Return the D valve to the system circulation position, then stop the vacuum pump.
d、Observe for at least 30 minutes to confirm the system pressure does not continue to rise.
3. Still leaking after maintenance? System troubleshooting checklist
If you still detect leaks after strictly following the above procedures, inspect according to the checklist below:
Step 1: Check the ground-glass sealing surfaces
• Have they been thoroughly cleaned to ensure no old vacuum grease residue, dust, or tiny particles remain?
• Are there any visible scratches, cracks, or damage on the surface?
Step 2: Check the vacuum grease
• Was a vacuum grease suitable for high-vacuum environments used?
• Is the amount applied moderate and even? Too little leads to poor sealing; too much can contaminate the system.
Step 3: Review operational details
• Was the vacuum sequence followed exactly? Incorrect rotation order is a common cause of failure.
• Were the valves turned enough times (3–5 turns) to ensure the vacuum grease is evenly distributed and air bubbles are expelled?
• Is the vacuum pump performing well and providing sufficient negative pressure?
Step 4: Check hardware condition
• Are glass components such as the vacuum cup, plug, and socket aged, cracked, or deformed?
The key to permanently curing repeated valve leaks is “grease” + “pressure” — both must be solid. Ensure the ground-glass surfaces are clean and the vacuum grease is properly applied, strictly follow the vacuum evacuation procedure specific to your system type, and make a habit of continuously observing pressure changes after maintenance.
