Understanding T-Port vs L-Port Directional Flows

Posted by Daniel Pishock on Jun 6th 2016


To understand "T"-port and an "L"-port  3 way valves and what makes them different, it's important to first establish what each of these terms mean.  By clearly defining each term, the difference in directional flow purpose will be easier to understand.  First, let's define exactly what a diverter valve does.

In simple comparison, a 3 way valve has one more port than a  2 way valve.  But why?  A two way valve allows a fluid to enter the valve from one  port, and exit through the other.  Having a third port, allows fluid an alternate path of travel, either when exiting or entering the valve.  This permits fluid to either exit the valve from more than one point, or enter the valve from more than one point.

Shop T-Port and L-Port Valves


What is a T-Port Valve?

T-ports and L-ports, while similar, do different things.  To accomplish this, the bore of the valve's ball is drilled in a particular shape.  A "T" shape allows one action, while an "L" facilitates another.  Both shapes provide options for diverting fluid flow from or to different sources, but each design offers unique functions.  In the case of a ball drilled with a bore in the shape of a "T," fluid can be directed to more than one location simultaneously: when the ball is in the open position, fluid is allowed to pass through the valve at full pressure to point "A" while allowing fluid to travel to point "B" at a slightly lower pressure.  In this way, a T-port 3-way valve is designed for directing fluid to multiple destinations.

What is an L-Port Valve?

An L-port valve on the other hand, performs the opposite function, and directs fluid from multiple sources.  For example, the use of an L-ported valve facilitates the ability to draw fluid from more than one source.  A simple turn of the handle changes the position of the ball inside the valve and allows a change in the drawing source.  Such as in, when one tank is empty, fluid can be drawn from the next.

T-Port vs L-Port Directional Chart

The Ball Valve Advantage

As illustrated earlier, "T" and "L" ports are made possible by drilling these shapes through a valve's ball.   Ball valves, particularly shut-off valves, provide superior seals against fluid travel.  Its unique design advantages make "T" and "L" bores possible, and this clever innovation allows you to have options when it comes to fluid control.

Where to Buy

Whether you need a T-port  diverter valve for directing fluid to multiple sources, or you want an L-ported valve for drawing fluid from different sources, you can find either valve with us at the ValveMan.com valve store. We carry both types, among a wide variety of other industrial grade valves. We've been in the valve business for over 50 years, and are happy to tell you all about the differences in valve types and configurations. That's because all we sell are valves. It's simply what we do, and we do it better than anyone else.