Apollo Valve 10-303 Series Bronze Safety Relief Valve, ASME Hot Water, 50 psi Set Pressure, 3/4" NPT Female: Industrial Relief Valves: Amazon.com: Industrial & Scientific
Guidance: Discharge from storage cylinders into pipework systems - CIBSE Journal
HYDRO MASTER Tankless Water Heater Service Valve Kit with Pressure Relief Valve 3/4-Inch IPS Isolator Clean Brass - Amazon.com
How Does a Pressure Reducing Valve Work? - Hot Water Cylinders LTD New Zealand
Unvented Hot Water Installation Regulations | hotun
This is leaking under my hot water cylinder. Trying to find an after hours plumber, but does anyone know how to fix it/make it stop for the time being? : r/diynz
Necessity of Vacuum Relief Valve - Not Pressure Relief Valve | Terry Love Plumbing Advice & Remodel DIY & Professional Forum