Process Valves > Control Valves > Lowflow Mark 708

 

Lowflow Mark 708 Fractional Flow Control Valve for Ultra-Low Cv

Lowflow's Mark 708 was developed to provide the most accurate control available for fractional flow services for pilot plant installations, test stands, R & D facilities or for specialized processes such as dosing, injection and venting applications. The Mark 708's rolling diaphragm design ensures that the effective diaphragm area remains relatively constant, regardless of valve stem position. A bolted body/bonnet connection simplifies maintenance — remove and replace the trim to change flow rates without removing the valve body from the process line.

Key Specifications

  • For steam, air, gas, oil, water, and chemical service
  • Cv ranges from 0.00001 to 4.0 available in 1/4" to 3/4" line sizes
  • Carbon steel or stainless steel body and bonnet, 14M rolling Nylon diaphragm, spring-loaded TEF/Chevron stem packing (good to 450° F)
  • Extended orifice, plug guiding standard for improved shutoff and accuracy

Specifications, Manuals, and Supporting Literature

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Model Selection Guide

Use this table to find the right model for your application.  Don't see the option you need? Call a Lesman sales specialist at 800-953-7626

Make one selection from each section of the chart. A finished model number
will look like this: 708SP025CS/PTT6ALA4T4S4A7

Description Catalog Number
Fractional Flow Control Valve with Side Mount HART Positioner, Threaded Ends, 316SS Trim and Teflon
Packing, Nylon/Nitrile Diaphragm, and Air Regulator for 14M Actuator
Dimensions (Inches) A B C D
Size and Body
Material
(For Temps >800°F,
Use SST)
1/4" Carbon Steel
1/4" Stainless Steel
1/2" Carbon Steel
1/2" Stainless Steel
3/4" Carbon Steel
3/4" Stainless Steel
7.25
7.25
7.25
7.25
7.25
7.25
11.6
11.6
11.7
11.7
13.5
13.5
0.9
0.9
1.2
1.2
1.2
1.2
6.3
6.3
6.3
6.3
9.5
9.5
708SP025CS/PTT6
708SP025S6/PTT6
708SP50CS/PTT6
708SP050S6/PTT6
708SP075CS/PTT6
708SP075S6/PTT6
Plug Seat Standard: Linear Hard
Standard: =% Hard
A
B
Max Allowable DP Rating A-T-O w/Pos
@40 PSI
A-T-C 3-15
@20 PSI
Flow Coefficient
CV
0.00001
0.00002
0.00005
0.0001
0.0002
0.0005
0.001
0.002
0.005
0.01
0.02
0.05
0.1
0.2
0.5
1.0
2.0
3.0
4.0
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
2350
800
666
532
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
5000
2065
650
541
432
A
B
C
D
E
F
G
H
I
J
K
L
M
N
P
Q
R
T
S
Range and Action 3-15 Direct
3-15 Reverse
A4T4S4
B4T4S4
Regulator None
Air Regulator for 14M Actuator
0
A7
Action Air-to-Close
Air-to-Close
D0G
R0G

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