| The Sure Flow Check valve is designed so that it is centralized
between the flanges when the stud bolts are in position. The outside diameter
of the body is equal to the bolt circle PCD minus the diameter of one bolt.
It is suitable for use in a variety of orientations. In horizontal lines
the valve is installed with the pins vertical (i.e. with the pin retainers
at the top). For sizes 6 " and upwards the valve is tapped to take
an eyebolt for lifting. Arrows cast into the body indicate the normal
direction of flow. Before initial installation it is advisable to open the
plates by hand since, if the valve is held in store for a period of time,
the corrosion inhibitor may have caused the plates to stick to the body
and line pressure may not be sufficient to break this seal. If the bottom
half of the studs are installed first they will serve as a platform to support
the valve whilst the gaskets and other studs are put in. Similarly, if the
valve is to be removed from the line, the top half of the studs should be
removed and the bottom half slackened.