INTRODUCTION

An outlet may be defined as a device constructed in a canal to deliver designed disc from a government channel to the field channel or water course ( cultivator’s channel). work which connects a government channel with the water course. Outlets are general provided on the main canal and branches, but are installed in such cases in the ditch dis taries constructed along the canals. In exceptional cases, when provided on main can branches these are called direct outlets. Since equitable distribution of the canal supp dependent on outlet, it must be such that it only passes a known and constant quantity water, but must only also essentially be a measure of the discharge.

CLASSIFICATION OF OUTLETS

The outlets are classified into three types, as under :

1. Modular Outlet : Also called modules or rigid modules. It is the outlet whose discharge Is independent of the water levels in the distributary and the water course within reasonable working limits. The outlet discharge is thus constant within the working limits. The loss of load through the outlet is more. This the type of outlet is either with moving parts or without moving parts. In the latter case, these are called rigid modules. Outlets with moving parts have disadvantages (i) Expensive being not simple to design and construct, and (ii) Liable to derangements due to increase in friction, rusting of the moving parts and any obstruction in the working of parts caused by silt and weeds in the canal water.

Gibb’s Module : It is the most common type of modular outlet. It essentially consists of a bell-mouth inlet pipe curved upwards from which water is led into an eddy chamber, semi-circular in plan, around which water flows giving rise to a free vortex flow (Fig 14,2).