Armfield S12-MKII, Инструкция по эксплуатации

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10
Description
Where necessary, refer to the drawings in the Equipment Diagrams section.
Overview
The equipment consists of a sand tank (21) that is mounted on a support frame (1)
with the necessary services, features and instrumentation to facilitate studies of
ground water flow, ground water abstraction, flood hydrographs and fluvial
mechanics.
Frame
The frame incorporates an adjustable foot (3) on each leg to allow the equipment to
be levelled. It is suggested that the top edge of the sand tank (21) be used as the
datum when levelling the equipment.
The frame incorporates a pair of scissor type jacks (34) at one end that allow the
sand tank to be elevated. The jacks are linked so that the sand tank remains stable
when raising or lowering. An indicator (36) shows the gradient of the sand tank. The
jacking handle is simply inserted into the coupling (35) on the front jack and rotated
clockwise to raise the sand tank or anticlockwise to lower the sand tank. The jacking
handle should be removed after adjusting the elevation of the sand tank.
CAUTION: Although the sand tank cannot move suddenly when adjusting the
elevation, extreme care should be taken when operating the jacks to prevent
crushing of fingers, hands or other objects between the upper and lower frames.
Water Feeds
A sump tank (4) and centrifugal pump (10) mounted in the frame, beneath the sand
tank, provide the water for the various demonstrations. Water exiting the sand tank
from the various outlets returns to the sump tank under gravity for reuse. An overflow
pipe (2) on the side of the side of the sump tank ensures that the tank cannot be
overfilled. A drain valve (6) is connected to a tapping at the base of the sump tank.
The centrifugal pump draws water from the sump tank via a tapping (9) at the base of
the tank. Water from the pump passes through two parallel feed arrangements, each
incorporating a filter (12), pressure regulator (11), feed flow control valve (13) and
variable area flowmeter (14). The pressure regulator in each feed ensures that the
flow is not affected by changes in the other feed provided that the regulator is
adjusted to suit. The outlet from each feed is terminated with a self-sealing quick-
release connector (15) that allows water to be fed to either end of the sand tank, the
spray nozzles or the river inlet tank as required via the appropriate flexible
connection. The self-sealing quick-release connectors allow rapid changes to the
configuration without the need for tools.
The outlet from the centrifugal pump incorporates a pressure relief valve to limit the
system pressure to a maximum of approximately 3.0 barg and prevent the pump from
overheating if the flow from the two outlets is restricted or stopped. Water discharging
from the relief valve is returned to the sump tank via a connection in the side wall of
the tank. When demand from the two outlets is high, the relief valve will remain
closed to maintain the pressure in the system. When demand is reduced and the
system pressure rises above 3.0 barg, the valve will open to relieve the excess flow.
The relief pressure is adjustable and set prior to delivery but instructions are included
in the Routine Maintenance section of this manual should further adjustment be
necessary.