Slide Rule for Control Valve Sizing

Technical Information

Catalogue No: C0920
Category: Personal/Personnel
Object Type: Stationery/Office Items
Object Name: Slide Rule for Control Valve Sizing
Part No: P2734
Serial No: ?
Manufacturer: Blundell Harling
Division: Unknown
Platform(s):
Year of Manufacture: 1967
Dimensions:
Width (mm):
Height (mm):
Depth (mm):
Weight (g):
Location: Archive Object Store
Inscription(s):

Fisher Control Valve Sizing Rule Mark VII

Notes:

In the 1950s and 1960s the Fisher Governor Company (now Fisher Controls International LLC a part of the Emerson Process Management Division of Emerson) developed specialist slide rules to aid in the selection of Control Valves for either liquid, steam or gas service.

This Fisher Control Valve Sizing Rule Mark VII was made by Blundell Harling (P2734) for GEC-Elliott Control Valves Ltd, Rochester, England, ©1967. This duplex plastic rule has 17 specialist scales for gases, steam and liquids from which the size parameters Cv, Cg or Cs can be determined given pressure drop, inlet pressure and flow rate, specific gravity (liquid) or inlet density (gas/vapour), temperature and degree of superheat (steam).

This imperial rule has a fabric backed PVC slip case. Several versions of the Fisher rule were made including one by Pickett for the American Fisher company.

Click to enlarge Click to enlarge Click to enlarge