Obviously, there are lots of different types of hydraulic manifolds and the definition may change a bit depending on who you are talking with at the time. So for these reasons, I am going to discuss 10,000 PSI hydraulic manifolds, with ⅜” NPT ports. These are the types of manifolds you would use with common, name brand, commercially available hydraulic pumps and systems. However, in all cases the word “manifold” is usually used when someone wants to describe the item which is used to help direct flow in the system. A very simple example of this would be what you may hear referred to as a “splitter” or a “y-piece”. This would take one incoming pressure line (P) and convert it into 2 separate outgoing pressure lines (P).
When talking about these “common” sorts of manifolds, there are a few different designs to consider. The designs we see most often are parallel, elongated parallel, polygon, controlled and ultimately controlled manifold assemblies.
A simple parallel manifold is the HM2 manifold which has 1 x ⅜” Female NPT port on one side and then 2 x ⅜” Female NPT ports on the other. This is what you would consider a very simple “splitter”.
An elongated parallel manifold is the HM4L which has 1 x ⅜” Female NPT port on one side and then 4 x ⅜” Female NPT ports on the other side. The big difference is that the entire length of the manifold is elongated so that there is more distance between ports. This makes it easier to physically install the hoses or quick connects next to each other.
A polygon manifold is like the HM5. It is hexagon shaped and has 6 sides. This configuration makes it so that the manifold can act like a hub to send pressure out in different directions without having to bend the lines. As with other manifolds, the ports which aren’t being used can also be plugged in order to make a particular directional design (3 way triangle shape).
A controlled manifold is one where a parallel manifold like the HM2 has needle valves included and this then would become the HM2C. It is a parallel manifold (HM2 Above) but the ports can be open and closed depending on where and when an operator wants pressure from that port.
The final type is the controlled manifold assembly like the HM4C-SU. This is a parallel design with incorporated needle valves but which is also fitted with gauges and quick connects. This means the operator can choose when and where they want pressure but they can also read how much pressure they have on any given line. The quick connects also allows the operator to remove lines easily from the manifold after use with little need for oily clean up.