Cla-Val 35 User Manual

CLA-VAL

•Provides High Capacity Venting f or Pipeline Protection

• Stainless Steel Trim Standard

• Stainless Steel Floats Guaranteed

• Fully Ported Valves - No Restrictions

•Designed For Drip Tight Seal At Low Pressures

The Cla-Val Series 35 Air and V acuum V alv e is designed to perf orm
two separate functions.First, it will allow large quantities of air to be
exhausted from the pipeline as it is being filled with water. When
this air has been vented completely, water will enter the valve
causing the float to seal tightly against the seat to prevent water
flow. Secondly, if the line is being drained, either intentionally or as
a result of pipeline breakage, the valve responds to the loss in
pressure and opens. This allows air to re-enter the pipeline and
prevents potentially damaging vacuum from developing.

Note: The Series 35 does not open under pressure to exhaust
small quantities of air which may collect at high points during
system normal operation. Series 34 Air Release Valve is required
for this function.

General Specifications

Sizes

1/2", 1", 2", 3" NPT
4" through 16"
125 lb.flanged ANSI Rated
250 lb.flanged ANSI Rated

Pressure Ratings

175 psi
300 psi

Temperature Range

Water to 180°F

Note: Specify when operating
pressure below 10 PSI

Materials

Body and Cover:

Cast Iron ASTM

A 126, Class B

Float:

Stainless Steel

Internal Parts:

Stainless Steel

Seal:

Buna-N® Rubber

Installation

Series 35 Air and Vacuum Valves should be installed at high
points or at grade changes within the pipeline. Mount the unit
in the vertical on top of the pipeline with isolation valve below
each valve in the event servicing is required. A vault with
adequate venting and drainage should also be provided.

Purchase Specification

The air and vacuum valve shall be able to automatically
exhaust large quantities of air during filling of a pipeline and
allows air to re-enter pipeline during the draining or when a
negative pressure occurs.

The inlet and outlet of the air and vacuum valve shall have the
same cross-section area as the pipe size. The float shall be
guided by a stainless steel bottom guide shaft.The 4" and larg­er valve floats shall have top and bottom guide shafts of
hexagonal cross section and hav e a protective steel discharge
hood.

The float shall be of all stainless steel construction guaranteed
to withstanding the design system surge pressure without f ailure.
The body and cover shall be concentrically located and of cast
iron and the valve internal parts shall be of stainless steel with
Buna-N

®

rubber seat.

The Air and Vacuum Valve shall be Series 35 from Cla-Val.,
Newport Beach, CA U.S.A

When Ordering, Please Specify:

1. Model Number

2. Inlet Size

3. Inlet Pressure Rating

Optional:

For anti-shock air valve shut-off order with
arrestor check device, order valve with
suffix “AC”see data sheet pages 32 & 33.

Series 35

Air and V acuum V alves

¤

TM

Air and Vacuum Valve Sizing

1. Series 35 Air and Vacuum Valves should be sized to handle the maximum amount of air to be exhausted or admitted into the
pipeline and not exceed an acceptable pressure differential across the valve.

2. Each high point or change in grade must be examined independently when determining valve size. Use the steepest slope
for calculations.

3. Use the flow capacity charts (A) and (B) on page 13 to assist sizing Air and Vacuum Valves.

4. Determine the smallest valve size capable of

exhausting air equal to the filling rate of the pipeline in CFS while

not exceeding a pressure differential of 2 psi across the valve orifice. (Based on pump capacity).

The following formula is recommended to calculate the rate of flow in CFS for filling the pipeline:

Where: CFS = Cubic feet per second

GPM= Gallons per minute

5. Determine the smallest valve size capable of

admitting air equal to the potential flow in CFS while not exceeding a pressure

differential of 5 psi across the valve orifice. (Based on gravity flow).

The following formula should be used to calculate the rate of flow in CFS that can occur within the pipeline under gravity flow
conditions. (Dur ing Initial Ffilling • During Intentional Draining • During A Pipeline Rr upture)

Where: Q = Flow of water in cubic feet per second

C = Coefficient in Chezy’s formula =110
S = Slope in feet per foot of length
D = Inside pipe diameter in inches

6. If thin wall pipe is being used, the risk of pipeline collapse due to the formation of vacuum must be considered. The following formula
may be used to calculate the collapsing pressure of thin walled cylindrical steel pipe using a safety factor of four:

Where: P = Collapsing pressure in psi

T = Thickness of pipe in inches
D = Diameter of pipe in inches

7. For other pipe materials or thickness consult pipe manufacturer for pipe collapsing pressure.

8. Determine the smallest valve size capable of admitting the required air in CFS (as found in step 5) without e

xceeding the

collapsing pressure (as found in step 6) or 5 psi, whichever is less. Do not exceed a pressure differential greater than 5 psi.

9. Finally compare the valve size determined in step 4 with the valve size determined in steps 5 or 6. If they differ, always
select the larger valve size.

Note: Cla-Val has available upon request, a Slide Rule Air Vacuum Valve Calculator that greatly reduces the amount of time
necessary to size valves for pipeline service.

P = 16,250,000

D

3

T

Q = .0007872 C S D

5

CFS =

GPM

448.83

AIR VA CUUM VALVE D ATA

CLA-VAL

TM

¤

CLA-VAL

'copyright Cla-Val 2003 Printed in USA Specifications subject to change without notice.

P.O. Box 1325 ¥ Newport Beach, CA 92659-0325 ¥ Phone: [phone] ¥ Fax: [phone] ¥ E-mail: [e-mail] ¥ Website cla-val.com

E-35 Sizing Guide (R-5/00)

4" Through 24" Sizes

1/2"Through 3" Sizes



8" through 16" available with flanged outlet in place of hood.

AND SIZING GUIDE

Series 35

CLA-VAL

'copyright Cla-Val 2003 Printed in USA Specifications subject to change without notice.

P.O. Box 1325 ¥ Newport Beach, CA 92659-0325 ¥ Phone: [phone] ¥ Fax: [phone] ¥ E-mail: [e-mail] ¥ Website cla-val.co

E-35 (R-5/00)

For sizes 18” and larger consult factory.

Model No.

350-AV.3
351-AV.3
352-AV.3
353-AV.3

Inlet Size

1/2” NPT

1" NPT
2" NPT
3" NPT

Outlet Size

1/2" NPT

1" NPT
2" NPT
3" NPT

Max.W.P.

300 PSI
300 PSI
300 PSI
300 PSI

Height

7"

9 1/2"

12"
12"

Width

6 1/8"

7"
9 1/2"
9 1/2"

Wt.Lbs

15
26
48
50

Model No.

354-AV

354-AV.3

356-AV

356-AV.3

358-AV
358-AV.3
3510-AV

3510-AV.3

3512-AV

3512-AV.3

3514-AV

3514-AV.3

3516-AV

3516-AV.3

4" FLG-125lb
4" FLG-250lb
6" FLG-125lb
6" FLG-250lb
8" FLG-125lb

8" FLG-250lb
10" FLG-125lb
10" FLG-250lb
12" FLG-125lb
12" FLG-250lb
14" FLG-125lb
14" FLG-250lb
16" FLG-125lb
16" FLG-250lb

4"
4"
6"
6"
8"

8"
10"
10"
12"
12"
14"
14"
16"
16"

200 PSI
500 PSI
200 PSI
500 PSI
200 PSI
500 PSI
200 PSI
500 PSI
200 PSI
500 PSI
200 PSI
500 PSI
200 PSI
500 PSI

17"
17"
20"
20"
23"
23"
26"
26"
31"
31"
34"
34"
34"
34"

12"
12"
14"
14"
18"
18"
20"
20"
24"
24"
27"

27"
30 1/2"
30 1/2"

105
115
160
175
208
255
370
400
590
640
681
740
879
930

Inlet Size/

Class

Outlet Size Max. W.P. Height Width Wt.Lbs

Chart A

Chart B

When Ordering,
Please Specify:

1. Model Number

2. Inlet Size (NPT)

3. Inlet Pressure Rating

4. Orifice Size

5. If Operating Pressure
Below 20 PSI

5
4

1/2"

1"

2"

3
2
1

0

0 2 4 6 8 10 1418 22 3040

PRESSURE IN P.S.I.

AIR FLOW DISCHARGE CAPACITY IN CUBIC FEET OF FREE AIR/SEC.

26

3"

5
4

4" 6" 8" 10" 12" 14" 16"

3
2
1
0

PRESSURE IN P.S.I.

2505075100 125 150 200 250 300 350 400 450 500 550 600 650 700 750

AIR FLOW DISCHARGE CAPACITY IN CUBIC FEET OF FREE AIR/SEC.