Maintaining Principle Valve Boxes

Since the box sits in the ground during the life of the system, there should be any maintenance on the box. Occasionally, the valve itself fails. If that is the case, the box must be removed, the tube cut, and a new valve installed. See PVC repair section for more information.

Installing Principle Valve Boxes

Construction

	Fill area below the valve box and inside the valve box with gravel. This will help with drainage and future maintenance of the valve.
	Place the lid on the valve box and backfill the work area. The area should be backfilled with dirt only. Rocks should be removed.
	This is the finished valve box. The lid is bolted to the box to deter vandalism.

Designing Principle Valve Boxes

Why is it Needed
The principle valve boxes will be located throughout the community and serve to isolate parts of the system for maintenance purposes. If your system does not have any shutoff valves, this is a good investment in the system as it makes maintenance quicker and has less impact on the community.

If the valve is located in a high-traffic area, the valve box should be robust enough to protect against tampering from children, livestock, or vandalism. Consider having the top locked. A simple nut and bolt should be enough to deter tampering. The water committee should keep the correct crescent wrench for opening the valve box.

The valve box could be a concrete box that sits in a hole in the ground and can be accessed without digging. Besides deterring vandalism, it also helps protect from any accidental machete or livestock damage. It also helps designate where the valve is located so that no digging is necessary to find the valve.

Design
In general, the point is to protect the valve without having the valve buried.  A simple concrete slab resting over a hole in the ground could work or a box as shown above.  There are many different design options that serve the same purpose.

Maintaining Domestic Valve Boxes

Since the cover sits on the ground during the life of the system, there shouldn’t be any maintenance on the cover. If the cover fails, it should simply be replaced by following the construction steps above.

Occasionally, the valve itself fails. If that is the case, the cover must be removed, the tube cut, and a new valve installed. See working with tubes section below for valve/component replacement.

Another type of failure is if something hits the top of the box causing the 1/2” tube to break at the intersection of the smaller tube and larger tube.  In this case, the valve will need to be replaced.

Building Domestic Valve Boxes

Time Required
1-3 hours

Materials List

Qty	Item	Notes
1	1/2” valve	Type shown in photos below
1	Hole saw
1	File
1	Can of PVC glue
1	hacksaw
1	2' length of 1/2” PVC
1	3' length of 3” PVC
1	Tin can (Large)	Form for concrete box cover that sits on valve
1	Sack of cement	Will only use small portion (less than 1/8 bag), For concrete box cover
1	Tin can of sand	For box cover
1	Tin can of rock	Small aggregate, pea-size preferable, For box cover

Construction – Valve Box

	Using the hole saw, drill hole on one side of the 3” tube. Repeat 180º on the other side of the tube.
	Using a flat file, bevel the edges of the valve until it can fit inside the larger tube. See picture below.
	Here is the valve fitting snugly in the larger tube. Align the valve with the holes that have been drilled into the sides of the tube.

Construction – Cover

<under construction>

Designing Domestic Valve Boxes

Why is it Needed
Domestic valve boxes are to protect against accidental damage with machetes and/or livestock. More importantly, they also serve to aid in the social engineering side of aqueduct maintenance. The valve at each tap stand can be shut off when someone has left the community (to avoid kids tampering) or to enforcement monthly water payments. Collecting a nominal fee each month will allow the water committee to have sufficient funds for maintaining their system without outside aid.

The domestic valve can only be opened and closed with a special key that only the water committee has.

Design
Valve box covers can be made from a concrete mix (1:2:4 with pea-size aggregate), using a tin can (large) as a form. 

Another option is simply using 3” PVC tube with an end cap.

Maintaining Cleanout/Shutoff Valves

The valves themselves should be protected from the sun, vandalism, etc. by some type of valve box.  If the valve is located in a high-traffic area, you may want a box that has a locking top.  If the valve is more remote, you’ll want some type of cover to protect against the elements (UV rays, machetes, livestock).

See the principal valve box section for box construction. In case the valve fails, it will need to be replaced. See section on PVC connections for more information.

Installing Cleanout/Shutoff Valves

Time Required
Less than 1 hour for installation

Materials List

Qty	Item	Notes
1	Valve	Dependent on size of tube at valve location
1	Cloth rag	For cleaning before gluing
1	Can of PVC glue

Construction
Installing the valves are pretty straightforward.  Cut into the tubes and install as needed.  This picture can be used as a guide.  This setup allows for the system to be shutoff and the cleanout opened so that the entire flow is redirected out the cleanout valve.  Cleanout valves can also be installed without a corresponding shutoff valve.

Designing Cleanout/Shutoff Valves

Why is it Needed

Shutoff valves are needed for system maintenance. There should be a shutoff valve at the intake structure(s), storage tank, and at the start of the distribution system if the tank is located away from the community.

Cleanout valves should be installed throughout the system in low points in the system or along long, flat runs where sediment can build up in the pipes. Opening the cleanout valve should be part of the quarterly maintenance program in the community.

Design

The picture to the left shows a cleanout valve and shutoff valve. The system can be shutoff so that all water leaves through the cleanout valve. A Y-shaped branch would be preferred to the T shown in the picture to put less stress on the fitting.

Maintaining Air Valves

Air valves occasionally fail, usually when they are placed in an incorrect location. If an air valve is located in a high pressure area, like a low point, the ball inside of the air valve will flutter up and down as it tries to release pressure. Eventually, this will wear out and fail.

Air valves that have worn out need to be replaced.