I. Professional Instrument Testing Methods
1. Humidity Tester Measurement Method
Use a dew point meter or humidity meter to directly measure the humidity inside the barrel.
The pharmaceutical industry requires a relative humidity range of 45%-75%.
The food industry recommends an absolute humidity of no more than 10 grams per cubic meter.
2. Air Tightness Test
Test the Steel Pail for leaks using an air pressure test. The test pressure is typically 20 kPa, maintained for 5 minutes with a pressure drop of no more than 10%.
Put the Steel Pail in a cool, dry place. Immerse the pail in water and observe for bubbles.
3. Hydraulic Test: Fill with water and let stand for 24 hours to observe for leaks. Pressurize to the specified value and hold for 30 minutes to check for leaks.
II. Simple Inspection Methods Without Specialized Instruments
1. Visual Inspection: Observe the inner surface of the barrel for water droplets, water marks, or moisture. Verify that the coating is completely dry: no fingerprints remain when pressing firmly with your finger.
2. Tactile Test: Quickly touch the inner surface to feel for dampness or coolness. Thoroughly dried material should feel warm and dry.
3. Water-Absorbent Test Paper: Apply dry water-absorbent test paper to the inner surface and observe for discoloration. Suitable for rapid testing of food-grade steel pails.
4. Small-Batch Trial: Fill a small amount of material and observe for any abnormal reaction. Especially suitable for demanding industries such as pharmaceuticals.
III. Drying Standards for Different Industries
1. Food-Grade Steel Pail Standards
Material requirements: 316L stainless steel, chromium content ≥ 16%, nickel content 10-14%
Surface roughness Ra ≤ 0.8μm
Residual chlorine concentration ≥ 0.5mg/L
2. Pharmaceutical-grade Steel Pail Standards
GMP standards require a temperature of 17-25°C and a humidity of 28%-60%.
Cleanroom temperature: 20-24°C and humidity: 45%-60%.
Tunnel sterilization and drying are required, with a temperature range of 100-350°C.
3. General Industrial Standards
Airtightness test: 20kPa, hold pressure for 5 minutes.
Drop test: airtightness must be maintained after a free fall from a height of 1.2 meters.
Load test: 1.5 times the nominal load capacity.
IV. Acceptance Points for Different Drying Processes
1. Hot Air Drying Steel Pail
Temperature is typically controlled between 60-80°C. Check that the hot air is evenly distributed to avoid local overheating. After drying, the steel pail must cool to room temperature before storage.
2. Centrifugal Drying Steel Pail
Inspect the barrel for deformation or weld damage.
Wall thickness uniformity tolerance ≤ ±0.3mm.
Pressure resistance test: static pressure ≥ 2.5MPa.
3. Vacuum Drying Steel Pail
Ensure no leaks when the vacuum level is ≤ 1Pa.
Inspect the seal for integrity.
Suitable for demanding industries such as pharmaceuticals.
V. Precautions
Ensure that any residual cleaning fluid is completely removed before testing.
Do not use open flames for testing Steel Pails that have been used to hold flammable or explosive materials.
Industrial-grade drying requires rust prevention measures.
Test records should be kept for at least 1.5 times the product's shelf life.
Regularly review inventory of Steel Pails, focusing on areas prone to rust.
