Theory? In whose universe, Dale?

In the latest entry of incompetence, Dale writes on LE:

In theory 2- 45° turns will have a larger radius turn and be less restrictive to air flow than a single 90° turn….

The FACT, Dale, is that a 45 bend has EXACTLY half the pressure resistance of a 90 degree bend. So two 45 degree bends EQUALS the pressure resistance of a single 90 degree bend. And because of the additional joint that could cause some turbulence, joining two 45 degree bends to form a 90 degree bend, there is a chance that the actual pressure resistance would be slightly higher than using a single 90 degree bend.

RUN FOR THE HILLS!!! ARMAGEDDON IS COMING!!!!

From the number of posts over the past couple of weeks on the various fora about meth makers using propane tanks to store anhydrous ammonia, you’d think that there was an epidemic of contaminated propane tanks out there that innocent glassmakers are going to get. Case in point (from LE):

NFP 58 - Liquified Petroleum Gas Code

This is the defining code for propane.

There are still people out there who think that it is OK to keep propane inside. So, without further ado, here are the salient portions of NFP 58:

6.2 Location of Containers

6.2.1 LP-Gas containers shall be located outside buldings unless they are specifically allowed to be inside of buildings.

6.2.2 LP-Gas containers shall be allowed in buildings only for the following applications:

(1) Cylinders as specifically provided for under Section 6.19 (see below).
(2) Containers of less than 125 gallons for the purpose of being filled.
(3) Containers on LP-Gas vehicles complying with and parked or garaged in accordance with Chapter 9.
(4) Containers used with LP-Gas stationary or portable engine fuel systems complying with Chapter 11.
(5) Containers used with LP-Gas fueled trucks complying with Chapter 11.
(6) Containers used on LP-Gas fueled vehicles garaged in accordance with Chapter 11.
(7) Cylinders awaiting use, resale or exchange when stored in accordance with Chapter 8.

***NOTE: These are the only allowed inside storage of LP cylinders under the code.

Thumbs down on Paragon kilns

As I’ve discussed previously, Paragon kilns do not follow the National Electrical Code (NEC) on the plugs that are used on their kilns. For example, their Bluebird kiln draws 14 amps, Paragon states the kiln requires a 20 amp dedicated circuit, but, believe it or not, they use a standard 15 amp plug.

Here’s an e-mail conversation I had with Arnold Howard of Paragon:

I am writing to you today to bring to your attention an issue that concerns me as a person who is deeply interested in safety in the glassworking studio. Recently, on several of the glassworking forums, issues have come up relating to people continually blowing circuit breakers and fuses when running their kilns. Naturally, I began to do some research and found that a large number of kilns that are available in the US, provided by your company and others, do not meet the requirements of the US National Electrical Code, sections 210.21 and 210.23.

More on in-line fans

I’ve been asked my opinion on the Vortex and CAN FAN in-line fans; so I did some basic research.

I can’t recommend the Vortex line simply because the manufacturer does not provide the static pressure curves for their fan lines. This is very important because you need to know how a given fan will perform in your exhaust system. A given fan might have a CFM output of 650 CFM at zero inches of static pressure (free air), but what is its output at a half inch or more of static pressure? It could very well be far less, and in that case, the fan is not meeting your design criteria.

Unbelievable, simply unbelievable

It must be very expensive to consult with an electrician, or hire a licensed electrician to have on your staff. I’ve just spent several hours going through the websites of the major kiln manufacturers: Paragon, Skutt, Jen Ken and AIM. Everyone one of these kiln manufacturers is in violation of the US NEC (National Electrical Code) on at least one of their kilns.

Let’s take Paragon as an example. Of their line of approximately 46 electric kilns, only 10 had the proper plug on the kiln power cord as well as the proper recommended circuit breaker for the kiln. Several of their kilns draw 20 amps, and Paragon uses a 20 amp plug and recommends a 20 amp circuit breaker!

No wonder people have problems using their kilns.

I can’t help but wonder if anyone at any of these kiln manufacturers even has a copy of the current NEC code, much less consults it on a regular basis.

I can certainly understand the design philosophy (although I totally disagree with it!) that they (the kiln builder) wants to have a kiln that will plug into an ordinary outlet (rated at 15 amps). But what I don’t understand is why they can’t simply build the kiln so that it draws a maximum of 12 amps.

There is no excuse for putting their customers at risk by providing equipment that does not meet the National Electrical Code.