How to choose the right valve for your IBC tank?

Introduction

Congratulations! You are doing a fantastic thing for the environment and your wallet by picking up a second-hand IBC tank (for Intermediate Bulk Container). These 1000-litre containers, often recovered directly from factories, are the ideal solution for your rainwater harvesting project.

However, once the tank is installed, a technical problem often spoils the party: the outlet valve.

• The original valve is worn, seized, or even unrecoverable.

• You have to replace it, but you find yourself faced with a jungle of cryptic numbers: S60x6, S75x6, S100x8...

Don't panic! This article is your complete guide to understanding the technical jargon, identifying the male thread of your vessel, and choosing the replacement valve with the perfectly compatible female inlet . This is the crucial step in ensuring the waterproofing of your rainwater collector installation!

1. What is a IBC Tank and Why Valve Replacement Is Essential?

IBC : The Container That Changed Water Reclamation

A IBC tank, or IBC (Large Bulk Container), is an industrial container designed to transport or store large volumes of liquids (often 1000 liters). Their robustness and metal frame (the cage) make them perfect for becoming high-capacity rainwater collectors.

Why Do I Need to Replace the Valve on Used Tanks?

When you buy a used IBC tank, the valve is the weak point:

• Wear/Non-conformity : It may have been used for non-food products or is damaged.

• Safety : To ensure a perfect seal in the long term, the replacement or addition of a quality adapter is necessary.

The issue is not the outlet of the new valve, but its entrance : the part that screws directly onto the tank. To do this, you need to know the crucial element: the male thread of your tank.

2. The Anatomy of the Problem: The Male Thread of the Tank (The True Output)

The Trap: Confusing Valve and Thread

Be careful, when we talk about "tank outlet", we are actually referring to the plastic male thread that is an integral part of the tank (the "nose" of the tank). The valve is screwed onto it.

The male thread is the "screw" present on the tank. The part you are going to buy (the replacement valve or adapter) should have a female thread that will perfectly match this "screw" of the tank.

If the female inlet of the valve you buy does not match the male thread of the tank, leakage is guaranteed, even with the best seal.

Deciphering the Thread Nomenclature IBC

Threads are designated by a simple but very precise formula that indicates their sizing:

S [Diameter in mm] x [Screw pitch in mm]

• S : Usually means that it is a Standard thread for IBC.

• The first digit (e.g. 60): Represents the nominal diameter of the valve in millimeters.

• The second digit (e.g. x6 or x8): Represents the thread, i.e. the distance between two ridges of the thread.

3. Focus on Threads: Their Differences

For your rainwater tank project, you will mainly come across these four types of industrial male threads:

The S60x6: the standard to be

It is the most common thread on 1000 liter IBC tanks in Europe. If you're not sure what to choose, check this one first.

• Detail: Coarse pitch or wide pitch thread (Buttress Thread).

• Diameter (theoretical): 60 mm.

• Thread: 6 mm (a turn of the screw moves the valve forward 6 mm).

• Your purchase: One S60x6 female inlet valve. It's the easiest to find.

The S75x6 and S80x6: The Superior Calibers

These calibers are less frequent, used on certain ranges or for higher flow rates.

• Detail: 6mm coarse-pitch thread (same as S60x6, only the diameter changes).

• Diameter (theoretical): 75 mm or 80 mm.

• Purchase: You will need to look specifically for an S75x6 or S80x6 female inlet valve.

The S100x8: The Coarse Step of Big Rides (Warning!)

It is the thread that most often causes purchasing errors.

• Detail: It is a coarse pitch thread, but its pitch is 8 mm, which is wider and more spaced than the 6 mm pitch.

• Diameter (theoretical): 100 mm. He's the biggest!

• Thread: 8 mm.

• Incompatibility: The 8 mm pitch is incompatible with all other 6 mm pitch threads, even if the diameter was similar (which is not the case).

• Careful: You must look for an S100x8 female inlet valve. For reference, a fine pitch would be of the BSP (standard valve) type, very different from these coarse industrial pitches.

4.How to Identify the Thread of your Tank WITHOUT ERROR?

Making the right measurement is the key to not wasting money on an incompatible adapter or valve.

The Mistake: The Gross Outside Measurement

The numbers 60, 75, 80 or 100 mm are nominal dimensions. They don't exactly match what you'll measure on the plastic.

• An S60x6 thread is actually about 58 to 59 mm in outer diameter (from one ridge of the thread to the other).

• An S100x8 thread measures approximately 98 to 99 mm.

The right 2-step method

1. Measure Diameter (Accurately)

Ideally, use a caliper. If you don't have one, a specific rule will do.

• Measure the outside of the thread, from one ridge of the thread to the opposite ridge.

• If you read:

  • 58-59 mm : This is an S60x6.

  • 73-74 mm : This is an S75x6.

  • 98-99 mm : This is an S100x8.

2. Determine the Thread (The Most Important Clue!)

This is what allows you to differentiate between the two main families of coarse pitches: 6 mm and 8 mm.

• 6 mm pitch (S60x6, S75x6, S80x6): The fillets are wide and widely spaced. This is the standard of coarse pitch IBC.

• 8 mm pitch (S100x8): It's an even wider and more spaced pitch than the 6mm.

If you attempt to screw a one-pitch valve onto a thread with another pitch, even a slight difference will prevent you from properly tightening the valve, causing a leak.

5. Your Targeted Purchase: Choosing the Replacement Valve (Female Inlet)

Once the male thread of your tank has been identified, the purchase becomes simple.

The Goal: The Room with the Proper Input

You must purchase either:

1. A complete new valve: It should have a female thread that matches your tank (e.g., an S60x6 female inlet ball valve).

2. A reduction adapter: If your tank is S100x8 or S75x6, you can buy an adapter (S100x8 female to S60x6 male). The adapter does the conversion.

The Standard of Exit (The Next Step)

Typically, replacement valves and adapters are designed to standardize the output to the most common form factor: the S60x6 male.

• If you buy a complete S60x6 female valve, its male outlet will also most often be an S60x6.

• If you buy an S100x8 female adapter, its male output will almost always be an S60x6.

This standardization allows you to have a common base to then connect all your watering accessories. But that's another story! By focusing solely on the compatibility between the male thread of your tank and the female inlet of your new valve, you ensure the tightness and longevity of your rainwater harvesting installation.

Good measures!