EFD 781S INSTALLATION GUIDE

Introduction

The 781S Series precision low volume low pressure
(LVLP) liquid spray valves are designed for high transfer
efficiency without overspray or airborne mist and provide
consistent coating of low to medium viscosity fluids.

781S Series valves are simple to use and will operate
many millions of cycles without maintenance. Spray valve
cleaning is accomplished by purging with the appropriate
solvent.

The 781S air cylinder body and fluid body are hard-coated
aluminum. The 781S-SS valve model uses stainless steel
throughout.

781S Series Spray Valve

INSTALLATION GUIDE

Electronic pdf files of EFD®manuals are also available at
www.efd-inc.com/manuals.html.

USA: 800-556-3484 or [phone]
Europe: 0800 585733 or [phone]
Asia: [phone]
[e-mail] www.efd-inc.com

®

A NORDSON COMPANY

Nozzle
air hose

Valve control
air hose

Fluid
supply line

Needle stroke
control knob

Stroke reference ring

Inlet fitting

LVLP spray valve

Installation

1. Mount valve with an EFD universal

valve mount (#7002VM) or other
fixture.

2. Connect the fluid supply line

to the fluid inlet port and to the
reservoir.

3. Connect the control air hose

(labeled “A”) and the nozzle air
hose (labeled “B”) to corresponding
outputs on ValveMate

™

controller

(or other pneumatic switch).

4. Fill reservoir by pouring fluid directly

into tank liner or manufacturer’s
bottle placed inside reservoir.
Secure cover prior to setting
pressure.

5. Set reservoir pressure to low for

thin fluids and higher for thick fluids.

6. Turn off nozzle air at the controller

regulator. Open the needle stroke
control one full turn. Place a cup
under the nozzle and actuate the
valve until fluid lines are free of air.

7.

Using the needle stroke control knob
on the 781S valve, set the fluid flow
rate to one or two drops per second.
Check flow rate by actuating the
controller in the time override mode.
Make valve stroke adjustments
when the controller is off.

8.

Set the nozzle air pressure on the
ValveMate 7040 controller to 10 psi
(.7 bar) and actuate the controller.
The valve will produce a fine spray.

To change fluid flow, use the needle
stroke control knob and/or reservoir
pressure.

To change nozzle air, use the
nozzle air pressure regulator. Higher
pressures will provide finer spray.

Output A

Output B

Prior to installing this valve, please
read the associated reservoir and
valve controller operating instruc­tions to become familiar with the
operation of all components of the
dispensing system.

1

5

4

3

Open

Close

7

Note: The area of spray coverage is determined by the distance
between the spray valve nozzle and the work surface. Refer to the
charts on the back page to determine this distance.

2

VALVEMATE

7040

6

8

To exhaust

To pressurize

VALVEMATE

7040

5

20

0