How can you tell whether a line is still under pressure before loosening a clamp? The Pre-Sure® Cap provides the answer: an instrumented Tri-Clamp cap that visually indicates the presence of fluid and pressure, with no sensor, no cable and no power supply. It is fitted in place of a standard cap, on the same ferrule.

 

 

Pre-Sure® Cap data sheet (PDF)

 

 

 

Pre-Sure® Cap, pressure-indicating Tri-Clamp cap

 

2-inch cap with dual visual indication, 316L stainless steel retainer and USP Class VI silicone diaphragm

 

2-inch Tri-Clamp end cap designed to visually indicate the state of a line before intervention. 316L stainless steel retainer, red USP Class VI silicone diaphragm, 316L tolerance to ASTM A240. First indication at 5 PSI (0.34 bar): the diaphragm partially extends and signals the presence of fluid. Second indication at 15 PSI (1.0 bar): it fully extends and signals definite pressure. Below 5 PSI, the button retracts and seals the opening. Direct replacement for a standard cap without ferrule modification. No spring, no power supply.

 

What it is for

 

The Pre-Sure® Cap addresses a recurring problem in process fluids: the operator who loosens a clamp without knowing whether the line is still pressurised. The usual consequence is well known: product spray, steam or caustic burns, contamination of the workstation. A standard cap gives no information. The pressure gauge is somewhere else.

 

The Pre-Sure® Cap replaces the end cap on the same 2-inch Tri-Clamp ferrule, under the same CIP cleaning and sterilisation conditions. The silicone diaphragm extends from 5 PSI and becomes clearly visible at 15 PSI. An operator can read the state of the line from a distance, without an instrument, before reaching for the wrench.

 

Typical applications: tank outlets, CIP drains, pump suctions, transfer panels, valve manifold ends. Anywhere a purge point or clamped end may remain charged with fluid or residual pressure after a line shutdown.

 

Replaceable diaphragm, stainless steel retainer that unclips without tools. Service life: 30,000 cycles or 6 months before diaphragm replacement, whichever comes first.

 

References

 

Reference	Designation	Connection
326 020	Complete Pre-Sure® Cap, 316L stainless steel retainer + silicone diaphragm	Tri-Clamp 2″
226 020	Replacement silicone diaphragm	Tri-Clamp 2″

 

Characteristics

 

Characteristic	Value
Connection	2-inch Tri-Clamp (DN 50.8)
Retainer	316L stainless steel, compliant with ASTM A240 M-316L, 32 Ra finish (0.8 µm)
Diaphragm	Red silicone, USP Class VI (USP 87 and USP 88)
First indication	5 PSI, i.e. 0.34 bar, presence of fluid
Second indication	15 PSI, i.e. 1.0 bar, pressure established
Maximum pressure	200 PSI, i.e. 13.7 bar
Continuous service temperature	90°C (195°F)
Maximum temperature for short cycles (SIP, CIP)	135°C (275°F)
Service life	30,000 cycles or 6 months before diaphragm replacement
Design	Passive, no spring, no power supply, water hammer protection
Safety	Fail-safe: if the diaphragm ruptures, pressure is vented through the retainer
Patent	US Patent Application No. 17/044,881

 

Frequently asked questions

 

At what pressure does the button become visible?

 

First extension at 5 PSI (0.34 bar), signalling the presence of fluid in the line. Full extension at 15 PSI (1.0 bar), signalling established pressure. Below 5 PSI, the button remains retracted and seals the opening hygienically.

 

Is it CIP and SIP compatible?

 

Yes. The silicone diaphragm withstands 90°C (195°F) in continuous service and tolerates 135°C (275°F) in short cycles such as SIP or hot CIP rinsing. Maximum allowable pressure 13.7 bar. To be checked against the actual CIP profile: caustic and acid temperature, contact time, cycles. The diaphragm is a consumable; include its replacement in the maintenance plan.

 

How is the diaphragm replaced?

 

The stainless steel retainer unclips without tools. Replacement diaphragm under reference 226 020. Recommended interval: 30,000 cycles or 6 months, whichever comes first.

 

What happens if the diaphragm tears?

 

The design is fail-safe: in the event of a rupture, pressure and product are vented through the orifice in the stainless steel retainer. No hidden pressure retention, no build-up behind a failed diaphragm.

 

Are diameters other than 2 inches available?

 

The standard catalogue lists only the 2-inch Tri-Clamp. For any other diameter requirement, confirm with the supplier.