Instruction Manual
D103211X012
NotchFlo DST Valve
March 2011
2
Table 1. Specifications
Available Valves
CL600 3‐Stage:
Level C only
CL900 and CL1500
v
NPS 4, 4‐Stage:
Levels A, B, and
C
(1)
CL1500
w
NPS 6, 4‐Stage:
Level C only
CL2500 6‐Stage:
Level C only
End Connection Styles and Ratings
(2)
Flanged:
Consistent with CL600, 900, 1500, and 2500
per ASME B16.34
Socket Welding:
Consistent with CL600, 900, and
1500 per ASME B16.34
Buttwelding:
Consistent with CL600, 900, 1500, and
2500 per ASME B16.34
Also see table 2
Shutoff Classification
Class V:
[5x10
12
m
3
/sec/bar/mm of port diameter
(0.0005 mL/min/psid/in) of water at service pressure
drop] per ANSI/FCI 70‐2 and IEC 60534‐4
Flow Characteristic
Linear
Flow Direction
Flow up
Approximate Weights
See table 2
1. Levels A, B, and C provide for varied pressure drops and capacity.
2. The pressure/temperature limits in this manual and any applicable standard or code limitation for valve should not be exceeded.
Figure 2. Fisher NotchFlo DST Trim
W8538-1
NotchFlo DST control valves utilize a high resistance, multi‐stage, axial flow path (or passage) where fluid flow is
parallel to the axis of the plug and cage.
Pressure reduction occurs throughout the length of the plug; thus individual stages aren't exposed to the full pressure
differential. Therefore, trim life is enhanced.
NotchFlo DST trim utilizes a series of notched flow restrictions and expansions to control the pressure drop of the
fluid. The amount of pressure drop per stage is controlled to prevent cavitation problems and minimize erosion issues.
Flow passage configuration provided by the multi‐stage plug and cage design make the NotchFlo DST valves
well‐suited for applications involving fluids with entrained particles. This is a potentially serious problem for other
anti‐cavitation valve designs which are subject to clogged flow passages.
Design of the trim allows for high rangeability.