Why does a War Reserve Case pressure test use positive pressure?

Answer: Under vacuum the walls close inward and a small leak hides; positive pressure loads the joint outward.

Can an accelerated run replace real storage?

Answer: Only partly. It covers compression set and desiccant saturation, not creep or corrosion.

Why two humidity probes rather than one?

Answer: The base condenses first, the lid line stays dry, so the higher reading governs.

What does the 600 kg test say about real capacity?

Answer: A proof load; service capacity is about one third, that gap covering creep.

Plate or laser code for the primary marking?

Answer: A plate, which survives a decade of UV; laser coding needs a coupon trial.

War Reserve Case Acceptance Standards: Tests and Limits

Quick answer: A War Reserve Case acceptance standard is worth only what a second inspector can reproduce, so every limit carries a test condition, not an adjective.

Which Metrics a War Reserve Case Standard Must Fix
From Storage Life Target to Accelerated Test
Judging Internal Humidity and Pressure Drop
Cycling, Stacking and Drop Conditions
Marking Durability and Inspection Frequency
FAQ

1. Which Metrics a War Reserve Case Standard Must Fix

An acceptance standard is not a list of adjectives. Write that the seal is good and two laboratories reach two verdicts; write charge to 15 kPa, hold ten minutes, lose no more than 0.8 kPa. A War Reserve Case is judged on seven groups, each with its condition.

Metric	Target	Condition	Judged
Storage life	60, 120 or 180 months	accelerated run	report front page
Internal RH	30 percent at five years	30 days, 40 °C, 93 percent RH	within 2 hours of opening
Pressure drop	0.8 kPa maximum	15 kPa charge, 10 minute hold	100 L baseline
Stacking set	3.0 mm maximum	600 kg, 72 hours, 40 °C	one hour after unloading
Climate cycling	no cracking, 20 cycles	55 °C against minus 25 °C	pressure re-test after
Marking	colour shift 3 maximum	300 hours UV	plus 500 abrasion strokes
Corner drop	still airtight	6 hours at minus 18 °C, 1.1 m	all three samples

2. From Storage Life Target to Accelerated Test

Storage life cannot be measured before delivery, so temperature does the work. On the rule that reaction rate doubles per 10 °C, 140 days at 60 °C stands in for five years at 23 °C, and 70 days at 70 °C does the same; a ten-year target runs it twice.

Acceleration is honest for compression set and desiccant saturation only. Shell creep changes mechanism by 70 °C, so a War Reserve Case stack stays a 72-hour physical test. Three samples per batch, two passing and one over fails the batch.

3. Judging Internal Humidity and Pressure Drop

After 30 days at 40 °C and 93 percent RH, the case is opened within two hours: five-year specifications allow 30 percent RH inside, ten-year ones 20 percent. Probes sit at the centre and 30 mm above the base, and the higher reading governs.

War Reserve Case: olive-green case open on a bench, dark foam in the lid cut into vial slots, packets in the lower tray

Pressure drop is measured in positive pressure, steadier than vacuum: charge to 15 kPa, hold ten minutes, allow 0.8 kPa. A 100 L interior is the baseline and every extra 50 L loosens the limit by 0.15 kPa, so a War Reserve Case of 150 L is judged at 0.95 kPa, after a four-hour soak at 20 plus or minus 2 °C. The breather valve is tested alone: it passes gas at 3 kPa and holds water at 0.5 kPa.

4. Cycling, Stacking and Drop Conditions

A cycle runs ten hours: four at 55 °C and 85 percent RH, two of transition, four at minus 25 °C. Twenty cycles make 200 hours, after which pressure drop may rise by 0.3 kPa at most and the rim must show no whitening.

War Reserve Case: a person in olive uniform carrying a closed case across gravel, a second case open with foam cut-outs

The 600 kg figure is a proof load, not a service rating. Service load is one third, about 200 kg, so four tiers of 55 kg cases put 165 kg on the bottom unit.

Drop testing is corner-only: six hours at minus 18 °C, then 1.1 m onto three corners. Inspect the latch keepers before re-testing pressure: a chipped keeper fails a War Reserve Case even when the seal holds.

5. Marking Durability and Inspection Frequency

An in-mould plate takes 500 abrasion strokes under a 1 kg rubber tip, holds colour shift within 3 after 300 hours of UV, and survives 50 ethanol wipes. Laser coding breaks up on the texture, so it stays auxiliary on a War Reserve Case.

Level	Trigger	Sample	Verdict
Routine	every batch	13 below 200 units, 20 below 500	2 accept 3 reject visual, 0 accept 1 reject functional
Type test	24 months or on material change	3	all items, any gap means a redo
Marking	every 12 months	5	abrasion and colour together
Storage review	at 36 months	2 per batch	humidity and pressure only

Salt spray for 96 hours belongs to metal plates and rivets, not plastics. A shorter calendar is not safer either: twelve-monthly type testing only pushes cost into the unit price.

Conclusion

An acceptance standard holds when its limits can be reproduced, not when it runs long: life from an accelerated run, humidity from stated bands, stacking from complete conditions, sampling from fixed frequency. With those fixed in the contract annex, a War Reserve Case reads the same in year five.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.