At the entrance to a pipe from a tank or reservoir the loss of head is dependent on the form of entry. For the simple type of inlet (Fig. 5.15a), the value of K is about 0*5; for the re-entrant type (Fig. 5.15b)

it is approximately 1*0. A bell-mouthed entry (Fig. 5.15c) is most efficient and reduces the value of K to about 0*05; this type is usually employed on the suction branch of pumps.