Rupture disc ? almost instantaneous response (<1 ms), zero leakage until activation, low cost, ideal for sudden discharges, corrosive fluids and processes where contamination is critical (pharmaceutical, food, semiconductors).
Pressure relief valve ? opens gradually and then closes, allowing the system to repressurize; suitable for frequent discharges or pressure modulation. It requires maintenance, seat tests, and may have minimal leakage.
In practice they are used combined: a disc upstream for a leak-tight seal and corrosion protection; a valve downstream for automatic reclosing. The choice depends on process criticality, the frequency of overpressure events and regulatory requirements.
Complete guide: Rupture disc vs pressure relief valve: differences and combined use