Fisher micro trims are used in those applications where the control of low flow rates is a requirement.
A variety of micro trims are offered that provide application solutions for standard and severe service conditions. This bulletin lists the various micro trims available and their service capability.
Standard Service Micro Trims
These are Plug-Characterized trims. Flow characterization is controlled by the plug.
(A)— Micro-Flow™—Ultra low flow control. Linear flow characteristic. Plug-characterized, port-guided.
Gas and liquid applications.
(B)— Micro-Flute™—Low flow control. Bridges the gap between Micro-Flow and Micro-Form trims.
Equal Percent flow characteristic.
Plug-characterized, port-guided.
Gas and liquid applications.
(C)— Micro-Form™—Equal percent, contoured plug used in a variety of valve designs.
(D)— Micro-Flat/Form—General service gas or liquid applications where high rangeability (>200:1)is required.
Severe Service Micro Trims
Cavitation Isolation Trim—controls where cavitation occurs in the valve to minimize trim damage.
Does not prevent formation of cavitation.
Cavitation Elimination Trim—trim design eliminates the effects of cavitation.
(E)— Micro-Flat™ Cavitation Trim—Cavitation isolation trim. Low Cv, is intended for use in angle valves only.
Not recommended for use in globe