uPVC Window Door Production Guide

Part 2 Drilling Drainage Holes and Pressure Balance Holes

This is uPVC window door production guide part 2. In this part, you could see how to make the drainage holes and pressure balance holes in the profiles.

Upvc windows and doors should have good performance for the water tightness.

This is to say that we must make drainage to let the water go outside. Meanwhile, we must make a pressure balance hole on the frame to make sure water goes outside smoothly.

According to the location and function, the holes include inside drainage holes, inside pressure balance holes and outside drainage holes, outside pressure balance holes.

1. which kind of holes should we make?

Normally we should according to some parameters to make the holes.

The size of the drainage hole and pressure balance hole please check the below information.

Drainage hole dimension ΦxL 5mm X 30mm

Pressure balance holes dimension ΦxL 4.5mm X 30mm

Drainage Holes

2. which kind of uPVC machines we use?

To make this kind of drainage holes and pressure balance holes, we have many different ways.

But normally we use the water slot machine to make. This machine has 2 or 3 heads. So it could finish the water slot process at one time.

Two Head Water Slot Milling Machine
3 Axis Water Slot Machine Drill

3. where and how many holes should we make?

In the uPVC window manufacturing process, we should know clearly where should we make the water slot and balance holes. And how many?

Before we start that, we should know where we should not make the holes.

>>> Some points we must notice

Do not make the drainage hole and reinforcement steel hole connected.

If this happens rainwater will go inside the main cavity. The reinforcement steel will be got rusted.

The location of the drainage holes should be at the lowest position of the drainage cavity.

This could prevent water accumulation inside the profile.

Inside drainage hole and outside drainage hole should have some distances. Please check the below picture.

uPVC window making machine

We offen use a drainage cap to cover the slot as decoration.

Water Slot Cap

>>> The situation must have drainage holes and pressure balance holes

  • Firstly, the uPVC window exterior should have a drainage
  • Secondly, the down frame of the exterior window door should have inside and outside the drainage hole.
Upvc Window Door Production Guide
  • The up frame should have a pressure balance hole and inside the profile should also have a balance hole.

>>> The quantity and location of the drainage holes

  • Firstly, if the downside frame length ≤700mm,
    make 1 drainage hole in the frame center.
  • Secondly, if the down frame length between 700mm and 1800mm,
    make 2 drainage holes. The position is 1/4 length from each ending side.
  • Moreover, if the down frame length ≥ 1800mm,
    makes 3 drainage holes. One in the frame center. And the other two at the 1/6 length from each ending side.
  • Generally speaking, each outside drainage should also have corresponding inner drainage.
Water Slot Hole
  • The position and quantity of the drainage holes should also accord the local weather and rainfall. In the heavy rainfall area, the quantity could be more, and dimension also could be bigger.
casement window water slot hole
  • Each frame or sash which has the glass installed should also have one or more pressure balance holes at the window door outer up frame.

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