API 661 Clause 7.1.6.1.5

[roca]

States:
"The lateral velocity in the header shall not exceed the velocity in the nozzle. Multiple nozzles or an increased header cross-sectional area may be required"

Can someone define what is meant by "lateral" in the above clause?

Thanks

 

[ione]

Lateral is referred to the stream flowing in the header. The velocity at which the flow stream travels through the header cross-sectional area is the lateral velocity.

 

[SNORGY]

In a typical air cooler header nozzle arrangement, the nozzles are located approximately in the center of the top or bottom of the rectangular header box. In Cartesian coordinates, inlet and outlet flow in the nozzles will be in the "Y" direction, and the lateral velocity along the header box will be approximately 50% of the mass flow along "+X" and 50% of the flow along "-X". The tubes, from the tubesheet, are oriented in the "+/-Z" direction. The lateral velocity is therefore the flow in a horizontal direction along the header box across the face of the tubesheet.

 

[roca]

Thanks for the replies guys..!