Air Preparation Products - Parker Fluid Control - #9

Air Preparation Products Selection Guide

Catalog 0700P-5/USA

This catalog gives you a flow rating (Cv) for each valve in the Parker Hannifin line. You can "plug" your requirements into the following simple formula, and determine the Cv needed to do the job. By not oversizing, you'll save space and money, and you'll ensure the valve you select will do the job. Converting the Job Requirements Into Cv (Capacity Coefficient).

Cylinder Area Cylinder Compression "A" (Sq. In.) X Stroke X Factor X (Table 2)

Cv = (See Table 1) (In.)_(Table 2)_

Stroke Time (sec.) x 28.8 Let's work through an example:

We want to extend a 3¹/₄" bore cylinder which has a 12" stroke in one second, and we have a supply pressure of 80 PSI to do the work. Here's what we know:

Cylinder Area for a 3-1/4" Bore, from Table 1.........8.30 sq. in.

Cylinder Stroke...............................................................12 in.

Stroke Time Required in Seconds..................................1 sec.

Compression Factor at 80 PSI, from Table 2......................6.4

"A" Constant for 80 PSI, from Table 2................................048

Substituting in the formula, we have:

8.30 x 12 x 6.4 x .048

^Cv = -nx288- = ^1.06

Any valve, therefore, which has a Cv of at least 1.06, will extend our cylinder the specified distance in the required time.

Your next step is to choose a basic valve design to do the job. For a quick guide to valve designs, see Table 3. Having selected the basic valve design, consult the Capacity Coefficient (Cv) tables which describe the individual valve capacities.

Having determined Cv, series, port size, flow-path configuration (pre-determined by circuit design), and actuation method, you're ready to choose the exact valve model number.

Read the pertinent catalog pages; note the exact model numbers, options and accessories you want. Then phone or write your Parker Hannifin air valve distributor. They will give you prompt, accurate service.

Note: Need circuit design help? Contact your local Parker Hannifin distributor. They are backed up by our regional Sales Engineers and offices. Between them, you'll find answers to all of your questions.

Note: Use "A" constant at 5 PSI AP for most applications. On very critical applications, use "A" at 2 PSI AP. You will find in many cases, a 10 PSI AP is not detrimental, and can save money and mounting space.

* Tabulated values are the solution of 68F and G =1 for Air.

where T is for

22.48 V(P₁ - P₂) P₂

3-Way and 4-Way

High flow capacities Minimum lubrication requirements Fast re sponse Self-cleaning poppet seats Pressures of 15 to 150 PSIG (modifications for vacuum to 250 PSIG) Low friction

Lower operating pressures Fast response Less wear

Long Cycle Life - Under pressure, radial expansion of the seal occurs to maintain sealing contact with the valve bore

Non-Lube Service - No lubrication required for continuous valve shifting Bi-Directional Spool Seals - Common spool used for any pressure, including vacuum

B. Spool Valves (WCS) 3-Way and 4-Way

4-Way

1. Wide range of flow capacities

2. Wide range of flow-path configurations

3. Pilot-operated models available

4. Pressures of vacuum to 150 PSIG

4-Way, manually operated

Inexpensive

Versatility in manual actuation

Cv - Capacity Coefficients (sometimes called Flow Factors). Each flow path through the valve has its own Cv value. All Cv ratings for each valve cataloged on this page are listed on the front side of this sheet.

Q = Flow In Standard Cubic Feet per minute

(14.7 PSIA at 60F)

P,= Inlet Absolute Pressure (gauge pressure + 14.7)

—— *\/^GT

22.48 \ (P₁ - P₂) P

P₂ = Outlet Absolute Pressure (gauge pressure + 14.7)

Note: P₂ must be greater than .53 x P₁ G = Specific Gravity of flowing medium (Air, G =1) T = Absolute Temperature of Air (460 + F.)

Cv = Q x "A" (Table 2)

Pneumatic Division Richland, Michigan www.parker.com/pneumatics