As professional Service Technicians we all should be aware of the potential issues surrounding the proper selection and use of the various safety valves available today.
First and foremost safety is critical…. Not only for the technician working on the espresso machine, but more importantly the safety of your customer, as well as their customer. It is amazing how stringent the test requirements are for certification for the 2 bar 10mm valve; examples:
– Lift of the sealing gasket is 1.74mm (not much):
– The overpressure variance when it opens is 10% or .2 bar
– The discharge rate is 969 liters/hr (256 gal/hr US).
ISPESL Certified Safety Valves vs. Non-Certified
A certified safety valve manufactured in Italy will arrive in the US Individually wrapped with a certification document enclosed, see diagram 2. In Italy, a certified valve is required to be used by law. Italy is so vigilant about safety valves they are required by law to be replaced every 2 years. The certified document should be given to the customer and a copy should be retained for your records with your service invoice.
A non ISPESL valve has not been certified….
A little known fact is that unless you are certified by ASME level 3,4 or 5 it is illegal to use a non certified valve. All safety valves in the US must pass API 527. This covers the standards for the test procedures and
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| Diagram 2 |
certifications required. Many European manufactures use non certified valves on new machines using in house certification.
If a non certified valve is in use most service companies will require that a certified valve be installed prior to the completion of the service. To understand if the valve is certified, see diagram 1. The rivet is what prevents adjustments to the valve. You may also find a safety wire with a lead seal. Another note once the valve has “let go” it should be replaced.
If in doubt replace it!! We anticipate the US adopting the 2 year replacement requirement in the future.
Terms:
– ISPESL: Intituto Superiorer La Prevezione E La Sicurezza
Del Lavro or referred to as Italia National Standard
– TUV: Techniscer Uberwachungsverein or referred to as
German National Standard
– ASME: American Society of Mechanical Engineers
– ETL: Edison Testing Labs
– UL: Underwriters Laboratoris