NS/NP General Description

The ASCO NS Series nuclear qualified valves include construction, material, and qualification improvements that typically increase the service (qualified) life of the comparable NP valve by a factor of two to three times depending on the application.

Specific improvements include:

• Elastomers :
  The standard ethylene propylene and optional Viton® fluoroelastomer have been replaced with a patent pending proprietary elastomer that ASCO identifies as Gamma +. This elastomer offers improved radiation resistance and longer thermal life over the standard elastomers in NP valves due to its increased resistance to high temperatures. In addition, Gamma + replaces both NP elastomer constructions (ethylene propylene and FKM fluoroelastomer.)
• Coils :
  ASCO NS Series valves are manufactured with a continuous-duty, Type N construction, fully encapsulated epoxy coil offering improved resistance to moisture and radiation and a longer thermal life. ASCO NP valves will be supplied with continuousduty non-molded varnish-impregnated Class H coils.
• Coil Leads :
  NS coil leads are 18-gauge multi-strand concentrically wound tinned copper wire with moisture-resistant insulation of polyether-etherketone (PEEK) that has a total diameter of approximately 1/16"". NP valves have a multi-strand 18-gauge wire
  with silicone insulation covered with fiber glass (an approximate 1/8" total diameter).
• NS Qualification :
  IEEE-323-1983, IEEE-344-1987,
  IEEE-382-1985, and IEEE-627-1980.
• NP Qualification :
  IEEE-323-1974, IEEE-344-1975,
  IEEE-382-1972, or 1980 (depending on qualification report), and IEEE-627-1980 (if included in qualification report).