Operation principle:
The heart of the PTV is a piston with both full and restricted flow ports for flow of the pilot gas. In the normal or restricted flow mode, gas flow through the PTV is allowed only through the restriction port. This port is normally 1.5 mm in diameter.

Accordingly, a leakage rate downstream of the PTV equivalent to an opening less than 1.5 mm will not cause a trip or closing of the PTV. The restriction port can be specified to a larger dimension, however actual release valves, fusible plugs or frangible bulbs must always be significantly larger effective bore than the restricted port bore diameter.

A spring positions the PTV in the normal mode when the downstream system is at the normal operating pressure. Upon the opening of a release valve, fusible plug or frangible bulb, air will escape from the system downstream of the PTV. Since the flow restricting port in the PTV is of significantly smaller area that the downstream opening, a pressure differential is created across the PTV piston.

The pressure differential is supplemented by the PTV spring, causing the piston to translate to the closed position. Flow through the PTV is then blocked and cannot be re-initiated until the downstream opening in the system is secured and the reset handle on the PTV is held open.

Operating the reset handle places the PTV piston in the full flow position (equivalent to the nominal bore of the system tubing. The reset handle is held open until the system pressure stabilizes to the normal operating pressure. The handle can then be released and the PTV returns then to the normal or restricted flow mode.

Connections/valve ends:
Inlet: 1/4" NPT ASME B1.20.1
Outlet: 1/4" NPT ASME B1.20.1
(Special inlets and outlets can be ordered upon request)

Body material: AISI 316L (EN 1.4404)
(Other materials can be ordered upon request)

Tests & Documentation:
Shell test: 1,5xPN acc. EN12266-1, Test P10 & P11 (test fluid: water)
Tightness-/leak test: 1,1xPN acc. EN12266-1, Test P12, leak rate A (test fluid: water)
Trip test: 2 barG closing pressure (test fluid: compressed air)

G.A. drawing with BOM.
Instruction & operation manual
EN 10204 - 3.1 material certificate
Declaration of conformity to PED.
Test certificate for Shell test, Leak test and Trip test.
(Other test can be ordered upon request)

For more details, see below data sheet and do not hesitate to contact us hereon.