LIQUID HELIUM (4.2 K) • BOIL-OFF RATE • VACUUM DECAY • PRV VENT HOLD-TIME
Liquid Helium Cryostat Dew Point & Boil-Off Hold-Time Calculator
Model cryogenic heat transfer into liquid helium (LHe) dewars and dilution cryostats: evaluate vacuum jacket pressure loss, multi-layer superinsulation performance, and hours to relief valve venting in transit.
Dewar Specifications & Vacuum Parameters CRYO-THERMODYNAMICS
Liquid Helium Volume
250 Liters
50 L
500 L
1,000 L
Multi-Layer Insulation (MLI Mylar Wraps)
40 Layers
10 (Basic)
40 (Standard)
60 (High-Spec)
Ambient Van / Trailer Temperature
20 °C (68 °F)
15°C (Climate Control)
30°C (Uncooled)
45°C (Desert Heat)
Pressure Relief Valve (PRV) Setpoint
10.0 PSIG
Boil-Off Dynamics & Transit Hold-Time
Calculated Heat Leak (Q)
0.82 Watts
Radiation + Conduction
Normal Boil-Off Rate (BOR)
1.18 % / Day
2.95 Liters / Day
Transit Hold-Time to Vent
96.4 Hours
4.02 Days Margin
Expansion Gas Volume
187.5 m³
750× Expansion at STP
Vacuum Safety Assessment:
Risk Status:
NORMAL STABLE (OVC SOUND)
Max Safe Transit Duration:
72 Hours (24h Buffer Reserved)
Request Cryogenic Logistics Plan
Export detailed boil-off curve analysis and emergency re-condensation plans for quantum cryostat transport.