Noz-Chek Valves

 

Design Features & Benefits


  1. Few moving parts — Disc is the only moving part, minimizing wear; 
  2. Axial movement of disc — Disc and seating configuration create a streamlined flow path with a venturi effect, resulting in low pressure drop;
  3. Short stroke of spring-assisted disc — Inlet flow velocity moves disc axially with a short stroke. In response to flow velocity reduction, a compressed spring initiates valve closure providing quick response.


Scope of Line

  • Sizes 2"– 60"
  • ASME B16.34, pressure classes 150 – 4500
  • Flanged, butt-weld ends, hubs ends and specials
  • Standard and short pattern
  • Wide range of materials of construction available.
    Consult factory for special application requirements


High Performance Non-Slam Check Valve

One of the most significant elements of piping system design is integrating the means to protect mechanical equipment and prevent damage caused by backflow. Backflow prevention is routinely achieved through the use of swing check and other style check valves.

Noz-Chek® valves are specifically designed for fast-reversing systems where backflow is a constant concern. In such critical service applications, Noz-Chek® Non-Slam Check Valves offer the following benefits.

  • Minimization of the damaging effects of water hammer in fluid systems
  • Removal of chatter associated with conventional valves in reciprocating compressor service
  • Protection of rotating equipment from damage due to flow reversal
  • Minimization of pressure loss in piping systems
  • Quick, dynamic response, reducing reverse velocity

 

Noz-Chek® is designed and manufactured to the highest quality standards.

 

INDUSTRY STANDARDS
API 598 Valve Pressure Testing and Inspection
ASME B16.34 Pressure/Temperature Ratings
ASME B16.5 and B16.47 Flanges
ASME Section III Rules for Construction of Nuclear Facility Components


Features

Extensive research and development combined with proven design principles, culminated in these unique Noz-Chek® features:

  • Few moving parts — Disc is the only moving part, minimizing wear.
  • Axial movement of disc — Disc and seating configuration create a streamlined flow path with a venturi effect, resulting in low pressure drop.
  • Short stroke of spring-assisted disc — Inlet flow velocity moves disc axially with a short stroke. In response to flow velocity reduction, a compressed spring initiates valve closure providing quick response.
  • Spring options — Choice of spring affects critical velocity and valve response. Selection is based on an engineering evaluation of specific applications. In absence of such evaluation, a standard spring will be provided.



Characteristics

Noz-Chek dynamic performance vs Swing-ChekNoz-Chek® valves deliver an effective dynamic response under various flow deceleration conditions. The dynamic performance characteristics of Noz-Chek® valves are compared to swing check and dual plate spring-assisted check valves in Figure 1.

 

Noz-Chek®’s unique design features result in superior performance, fast response and lower pressure loss in piping systems.

 

 

 

 

 

 

Opening

Noz-Chek Opening

Reduced pressure, generated by increased velocity in the minimal flow area, creates additional force assisting the disc to open and allowing for extra spring loading that facilitates a faster closing time.

This spring force is balanced in the fully open position.

The Noz-Chek® is designed to mainatin the disc in a stable open position even during moderate flow oscillation.

 

 

 

 

 

Closing

 Noz-Chek Closing

When a noticeable reduction in flow occurs, the disc reacts immediately, limiting backflow and valve slamming.

The spring load, low mass disc, and short displacement ensure a rapid self-dampening response.

For unique applications, the internal geometry can be modified to suit the service conditions.

 

 

 

 

 

 

Noz-Chek Valve Cross-Section - Benefits

 

Applications Flow Outlet Zone Spring
  • Feedwater
  • Cooling water
  • Blowdown
  • Steam
Designed for pressure recovery to minimize pressure loss and fluid turbulence. Results in smooth flow. Being an indispensable component, it is designed and specified for the particular service conditions required by the customer’s application

 

Disc Seat Flow Inlet Zone
Standard disc is high strength with minimized weight to provide fast dynamic response. Design minimizes bearing loads, lengthening the life of bearings and shaft. Offered in a variety of trim materials, with metal or resilient seating. Assures venturi flow by its configuration. Provides seating surface for disc and enables bubble-tight seal with resilient materials. Venturi design maximizes flow impact on disc. Provides streamlined flow when valve is fully open to minimize pressure loss.

 


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