6
3.2 Plumbing
The recommended plumbing for the instrument is shown in Figure 4.
The instrument is designed to require very little head pressure to operate;
around 6.9kPa (1 PSI). Flow requirements are 100ml/min. – 1.5 liter/min.
(0.026-0.40Gal/min). The pressure regulator will allow for a maximum
pressure of 1380kPa (200 PSI.). The maximum allowable fluid
temperature is 50°C (122°F).
An optional flow regulator Cat# 19778 can limit flow to around 1 liter/
min. this is not recommended for applications involving sea water.
Figure 4: Recommended Plumbing for the Instrument
Intake Tubing
Connection
4.75mm (
3
⁄
16
inch)
I.D., 8mm (
5
⁄
16
inch)
O.D. tubing should
be connected here
to supply the sensor
with a dependable
sample flow
Drain Vent
Leave open for
gravity-feed and
open-drain systems.
Plug with a #6-32
sealscrew for
pressurized systems.
See manual for
details
Backpressure
Valve
This valve allows
adjustment of the
amount of back
pressure, which
will help to control
flow rate and
eliminate small
bubbles
Shutoff Clamp
This clamp
allows for
shutoff of the
intake flow
during cuvette
cleanings and
replacements
Drain Tubing
Connection
4.75mm (
3
⁄
16
inch)
I.D., 8mm (
5
⁄
16
inch)
O.D. tubing should
be connected here
to route the sensor
drain tubing to a
suitable site drain
Connector Assembly
Insert
Nut
Tubing
(not supplied)
The instrument is equipped to be plumbed using 4.75 mm (
3
⁄
16
") ID,
8 mm (
5
⁄
16
") OD flexible tubing. Opaque tubing should be used if the
tubing will be exposed to sunlight, to prevent algae growth.
Model 28042 is equipped with a flow switch. For this instrument
the user connections are equipped with ¼" push-to-connect
connections. The suitable tubing is polymer or copper tubing
with a ¼ inch OD. These connectors cannot be used with
stainless steel tubing.
NOTICE
In figure 4, there are two operator controlled flow adjustment devices
shown. The one on the input side is a shutoff clamp used during cuvette
maintenance. The other device, located on the output side of the flow cell,
is a backpressure valve. Backpressure may be required to prevent air from
coming out of solution, which may be observed as tiny air bubbles.
3.2.1 Pressurized Systems
A standard feature of the AccUView LED is a pressure regulator. The
regulator is rated for use up to 1380 kPa (200 PSI) and will lower the
pressure down to a pressure more suitable for use in the AccUView
LED. If inlet pressures can exceed 325 kPa (47 PSI) use appropriate
tubing to connect to the AccUView LED. An optional flow regulator can
be used to limit the flow to 1 liter per minute.
3.2.2 Drain Vent
The AccUView LED has been fitted with a drain vent in the “OUT”
bulkhead fitting. This fitting allows for atmospheric equalization, thus
helping to alleviate bubble formation in the cuvette. Refer to Figure 4.
Upon initial flow minor leakage may occur through the drain vent. This
will subside once normal flow is established.
For some high pressure systems, where the vent hole continuously
leaks, a 6:32 seal screw is provided which should be inserted into the
vent hole and tightened.
The drain water from this instrument should NEVER be reintroduced
back into the incoming water stream. This water MUST be directed
to a convenient drain.
NOTICE
