🔍 Key Concepts

• Safety heads on large reciprocating compressors are designed to lift or blow off safely if pressure gets too high • How refrigeration compressor relief devices are held in place but can still move/open under over‑pressure • The difference between a fixed attachment (like welding) and a removable/loaded attachment (like springs or pressure force)

💭 Think About

• On an over‑pressure event in a large reciprocating compressor, what has to physically happen to the safety head so the compressor is protected? • Which of these options would allow the safety head to stay tight in normal operation but move or lift quickly and repeatedly if needed? • Which method would maintenance personnel reasonably be able to disassemble and reassemble during routine service?

✅ Before You Answer

• Eliminate any methods that would make the head non‑releasable or very hard to remove for maintenance (think about welding). • Consider which choice provides a controlled, reusable holding force rather than a one‑time or purely pressure‑dependent attachment. • Ask yourself which device type is commonly used in mechanical relief arrangements to hold parts seated but still allow them to lift under excess pressure.