Vapor Pin™

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Vapor Pin™ Frequently Asked Questions

How is the Vapor Pin™ better than existing methods for sub-slab vapor sampling?

The Vapor Pin™ is superior to other sub-slab vapor sampling methods because: 1) it's constructed of a single piece of metal, eliminating potential leak points; 2) it's installed in minutes using common hand tools; 3) it uses a silicone sleeve to form an air-tight seal between the Vapor Pin™ and the side of the borehole, eliminating the need for grout or other adhesives; and 4) unlike other sampling devices, it's easily retrieved for reuse.

What do I need to install a Vapor Pin™?

The Vapor Pin™ is installed easily using common hand tools. We recommend purchase of the Vapor Pin™ Kit, which includes just about everything required for 10 Vapor Pin™ installations. The only tools needed (in addition to the Vapor Pin™ Kit) are a hammer drill and appropriate bits, and a dead blow hammer. See the Vapor Pin™ Standard Operating Procedure for details. Grout or other adhesives are NOT required.

What kind of drill and bits does Cox-Colvin use during Vapor Pin™ installation?

We use a hammer drill manufactured by Hilti (TE 50 Deluxe Grounded Combihammer, item # 383916), with hammer drill bits TE-YX 5/8" x 22" (item # 206514) and TE-YX 1-1/2" x 23" (item # 293032). Available by calling 1-800-879-8000 or by clicking here. Comparable drills and bits are available from other manufacturers as well.

Exactly what's included in the Vapor Pin™ Kit?

The Vapor Pin™ Kit consists of the following items, all conveniently contained in a Hard-sided Carrying Case: 10 Vapor Pins™; 20 Silicone Sleeves, 20 Vapor Pin™ Caps, 10 Flush Mount Covers; 1 Installation/Extraction Tool; 1 Brush; 1 Water Dam for leak testing; 1 Vapor Pin™ Standard Operating Procedure. We recommend that you initially purchase a Vapor Pin™ Kit to ensure all required components are obtained. After that, individual components of the Kit can be purchased as needed.

How long does it take to install a Vapor Pin™?

The Vapor Pin™ can be installed and ready for sampling in a matter of minutes.

Does the Vapor Pin™ provide a tight seal against the slab?

Under normal circumstances with proper installation through a concrete slab, the Vapor Pin™ provides an air tight seal. Cox-Colvin has leak tested the Vapor Pin™ with helium; with 99% helium in the leak-test shroud, no helium (<50 ppm) was detected in soil gas. Some situations, such as a thin concrete slab or cracked and degraded concrete in a hole greater than 5/8-inch diameter, may result in a poor seal. We recommend leak testing as part of the sampling procedure.

How long after installation before I can sample a Vapor Pin™?

Because the Vapor Pin™ does not require the use of grout, it can be sampled as soon as the sub-slab soil gas conditions equilibrate. The period of time will be prescribed by your particular guidance, but can be as soon as 20 minutes following installation.

Cox-Colvin typically purges soil gas with a combination photo-ionization detector (PID) and oxygen (O2) meter, and collects the sample after the PID and O2 levels stabilize, indicating the presence of undiluted soil gas. In our experience, the Vapor Pin™ typically needs to be purged of about 50 ml of soil gas before stabilization.

Will the silicone tubing surrounding the Vapor Pin™ affect my sample?

We use peroxide-cured silicone tubing with the Vapor Pin™. Our studies indicate that the tubing does not affect the sample results. The tubing is used in two places - surrounding the bottom half of the pin (forming the seal between the drilled hole and the Vapor Pin™), and as a connector between the Vapor Pin™ and the tubing that leads to a Summa Can or other sample container. In both cases, sub-slab vapors are exposed to very little of the silicone tubing.

What kind of sample tubing do you recommend for the Vapor Pin™?

We recommend using 1/4" outer diameter (OD) nylon or teflon tubing. Cox-Colvin offers Nylaflow® LM tubing, which has better chemical properties than generic nylon, and is less costly than teflon. As with all environmental sampling, make sure your equipment complies with your regulatory requirements and Data Quality Objectives.

How do I connect semi-rigid sample tubing to the Vapor Pin?

Because the Vapor Pin was designed to be rugged and compatible with other sampling hardware, it has a nominal 1/4" barbed fitting at the top. Like other barbed fittings, it is actually somewhat larger than 1/4" in diameter, so the Vapor Pin™ is joined to semi-rigid tubing with a short piece of soft tubing. Cox-Colvin offers Tygon® R-3063 tubing, which offers better chemical resistance than other soft tubing, but is pliable enough to make a tight seal.

Although Tygon® is regarded as having better chemical resistance than silicone, silicone's high flexibility makes it better to connect tubing and hardware of different diameters. We've used Tygon® and silicone for collecting soil gas through tubing with a hypodermic syringe, but silicone is easier to puncture and it seals around the hole upon withdrawal of the needle. High quality silicone tubing also is available from Cox-Colvin.

Please notice that chemical interference from tubing is dependent upon many factors, but tubing is more likely to contribute hydrocarbons than chlorinated compounds. To minimize the risk of chemical interference, reduce tubing lengths as much as possible (particularly soft tubing), and keep tubing away from vapor sources.

How do I connect semi-rigid sample tubing to a "Summa" canister?

Most Summa-type canisters and regulators are equipped with Swagelok™ compression fittings. These fittings connect to 1/4" outer diameter (OD) tubing with Swagelok™ ferrules and a hexagonal nut. The nut can be reused, but the ferrules are used only once. Many laboratories can provide Swagelok™ ferrules and nuts together with sample containers.

What is the preferred seal to use with the Water Dam?

The preferred seal is a VOC-free modeling clay. Brand names may change their formulation, so specific brands are not suggested. However, a good substitute is Play Doh. Play Doh is a food grade product and forms an effective seal. Internet searches also can be used to obtain details for making a Play Doh substitute at home.

Can the Vapor Pin™ be installed as a flush mount?

Yes, the Vapor Pin™ is designed to be installed as a flush mount. Flush mount covers are supplied with the Vapor Pin™ Kit. The Vapor Pin™ also can be installed as a stick-up option in situations where the Vapor Pin™ will be removed immediately after sampling.

Can I leave a Vapor Pin™ in place between sampling events?

Yes. The Vapor Pin™ can stay in place as long as necessary. For repeated use, we recommend a flush mount installation to protect the pin from damage. Keep in mind that the flush mount cap is not water tight and should not remain in place in areas subject to spills or leaks. If future sampling is not required, Vapor Pin™ should be removed and the hole in the slab filled with hydraulic cement.

Will the Vapor Pin™ leak vapors into the building if I leave it in place?

If properly installed and the protective cap is utilized, there should not be leaking of vapors into the structure via the Vapor Pin™.

Will the Vapor Pin™ cause damage to the floor?

Installation of the Vapor Pin™ will result in a 1.5-inch diameter hole (flush mount installation), or a 5/8-inch hole (stick-up installation). After the Vapor Pin™ is removed, the hole should be patched with hydraulic cement. Beyond this, there should be no damage to the floor.

Can the Vapor Pin™ be used in slabs of any thickness?

The Vapor Pin™ was designed to be used in slabs that are at least three inches thick. If the Vapor Pin™ will be installed as a flush mount, we suggest that the slab be at least four inches thick. The upper limit on the thickness of the slab is determined by the length of the drill bit employed. The base of the Vapor Pin™ does not have to extent to the base of the slab. We suggest a 24-inch length drill bit to cover most situations.

Can a Vapor Pin™ be re-used after extraction?

Yes. The Vapor Pin™ is designed to be re-used after removal from the slab. The Vapor Pin™ can be re-installed and re-used an indefinite number of times. The sleeve and the protective cap should be replaced with each use and the Vapor Pin™ should be properly decontaminated in accordance with Standard Operating Procedure.

How do I decontaminate the Vapor Pin™ between installations?

The Vapor Pin™ decontamination procedures, which are provided in the Standard Operating Procedure, consist of removing the silicone sleeve and protective cap, cleaning the Vapor Pin™ in an Alconox solution, rinsing thoroughly, and heating to a temperature of 130°C.

Can the Vapor Pin™ be used for vapor intrusion sampling?

The Vapor Pin™ was designed for use in vapor intrusion studies as well as source delineation. We do suggest a flush-mount installation and that your applicable guidance be consulted to obtain appropriate leak detection procedures, soil gas flow rates, appropriate sample containers, and appropriate length of the sampling period. The Vapor Pin™ should be left in place if multiple rounds of sampling are required.

Can the Vapor Pin™ be used to sample all VOCs?

The Vapor Pin™ provides a means of transmitting soil gas through the slab so that it can be sampled. The particular suite of VOCs that will be reported is dependent on the analytical method employed by your laboratory.

Does anyone else make something like the Vapor Pin™?

We're not aware of another device quite like the patented Vapor Pin™. Other types of sub-slab sampling devices are available and many practitioners construct their own sub-slab devices. These devices are often constructed of several pieces and require cementing in place. Once installed, they typically are not removable and cannot be used again. We believe the Vapor Pin™ will become the new standard for sub-slab vapor sampling because it's so easy and quick to install and collect samples. Plus, you can use the Vapor Pin™ over and over.

Have a specific question not addressed above? Email us or call (614) 526-2040.