Monoblock & Sectional Valves

Sectional Valves

Sectional valves have the benefit of being able to add or remove a section as needed. Being able to stock individual sections and build an array of different valve setups makes for less money tied up in stocking and versatility in production. This also makes servicing these valves much easier since you can remove and replace a section and your system is quickly back up and running.
Many sectional valves are built to cover a broader range of higher pressures and flows that many monoblock valves can’t handle. A sectional valve can even functionally work in the place of any monoblock setup but they do have some negative qualities to be aware of. With each section added to the valve, the potential leak points increase as well. There are many different serviceable parts and, when being serviced, if the tie rods that hold the valve together are not torqued correctly then the valve will either leak or the spools will not shift properly.

Monoblock Valves

Monoblock valves are typically much cheaper than sectional valves, which makes them the first option considered in most systems. They are lightweight and significantly more compact than a sectional valve. An often overlooked benefit is that the monoblocks do not have the sectional leak points mentioned above. This prevents many installation and service problems.
Monoblock valves are not without their challenges. Since the entire valve is one casting, if it ever needs to be serviced then the whole valve must be removed. If there is a major problem with a section, the whole valve has to be scrapped, which is more expensive than just replacing a single bad section of a sectional valve. Most monoblocks are targeted for lower to medium flows and pressures, which helps keep cost, weight, and size down but also limits the applications they can be used in.