1 When brazing with cadmium bearing materials or when cutting on such materials increased rates of ventilation may be required.2 Nearest half-inch duct diameter based on 4,000 feet per minute velocity in pipe. 1910.252(c)(3)(ii) Fixed enclosure. A fixed enclosure with a top and not less than two sides which surround the welding or cutting operations and with a rate of airflow sufficient to maintain a velocity away from the welder of not less than 100 linear feet (30 m) per minute. 1910.252(c)(4) Ventilation in confined spaces - 1910.252(c)(4)(i) Air replacement. All welding and cutting operations carried on in confined spaces shall be adequately ventilated to prevent the accumulation of toxic materials or possible oxygen deficiency. This applies not only to the welder but also to helpers and other personnel in the immediate vicinity. All air replacing that withdrawn shall be clean and respirable. 1910.252(c)(4)(ii) Airline respirators. In circumstances for which it is impossible to provide such ventilation, airline respirators or hose masks approved for this purpose by the National Institute for Occupational Safety and Health (NIOSH) under 42 CFR part 84 must be used. 1910.252(c)(4)(iii) Self-contained units. In areas immediately hazardous to life, a full-facepiece, pressure-demand, self-contained breathing apparatus or a combination full-facepiece, pressure-demand supplied-air respirator with an auxiliary, self-contained air supply approved by NIOSH under 42 CFR part 84 must be used. 1910.252(c)(4)(iv) Outside helper. Where welding operations are carried on in confined spaces and where welders and helpers are provided with hose masks, hose masks with blowers or self-contained breathing equipment approved by the Mine Safety and Health Administration and the National Institute for Occupational Safety and Health, a worker shall be stationed on the outside of such confined spaces to insure the safety of those working within. 1910.252(c)(4)(v) Oxygen for ventilation. Oxygen shall never be used for ventilation. 1910.252(c)(5) Fluorine compounds - 1910.252(c)(5)(i) General. In confined spaces, welding or cutting involving fluxes, coverings, or other materials which contain fluorine compounds shall be done in accordance with paragraph (c)(4) of this section. A fluorine compound is one that contains fluorine, as an element in chemical combination, not as a free gas. 1910.252(c)(5)(ii) Maximum allowable concentration. The need for local exhaust ventilation or airline respirators for welding or cutting in other than confined spaces will depend upon the individual circumstances. However, experience has shown such protection to be desirable for fixed-location production welding and for all production welding on stainless steels. Where air samples taken at the welding location indicate that the fluorides liberated are below the maximum allowable concentration, such protection is not necessary. 1910.252(c)(6) Zinc - 1910.252(c)(6)(i) Confined spaces. In confined spaces welding or cutting involving zinc-bearing base or filler metals or metals coated with zinc-bearing materials shall be done in accordance with paragraph (c)(4) of this section. 1910.252(c)(6)(ii) Indoors. Indoors, welding or cutting involving zinc-bearing base or filler metals coated with zinc-bearing materials shall be done in accordance with paragraph (c)(3) of this section. 1910.252(c)(7) Lead - 1910.252(c)(7)(i) Confined spaces. In confined spaces, welding involving lead-base metals (erroneously called lead-burning) shall be done in accordance with paragraph (c)(4) of this section. 1910.252(c)(7)(ii) Indoors. Indoors, welding involving lead-base metals shall be done in accordance with paragraph (c)(3) of this section. 1910.252(c)(7)(iii) Local ventilation. In confined spaces or indoors, welding or cutting operations involving metals containing lead, other than as an impurity, or metals coated with lead-bearing materials, including paint, must be done using local exhaust ventilation or airline respirators. Such operations, when done outdoors, must be done using respirators approved for this purpose by NIOSH under 42 CFR part 84. In all cases, workers in the immediate vicinity of the cutting operation must be protected by local exhaust ventilation or airline respirators. 1910.252(c)(8) Beryllium. Welding or cutting indoors, outdoors, or in confined spaces involving beryllium-containing base or filler metals shall be done using local exhaust ventilation and airline respirators unless atmospheric tests under the most adverse conditions have established that the workers' exposure is within the acceptable concentrations defined by 1910.1000 of this part. In all cases, workers in the immediate vicinity of the welding or cutting operations shall be protected as necessary by local exhaust ventilation or airline respirators.
This seemingly quick and flexible installation does have its downfalls, though. No single pipe/tubing system used in the US has been 100% problem free, and PEX is no exception. Some of the disadvantages of PEX include:
Pipe Flow Advisor Crack Free 18
Response to Martin HolladayIt seems to me that as an "advisor" for this site that the words you choose should be well thought out before posting. Most does not equate to many. Gas stoves have been around since the late 1800's. These scare tactics of deathly illnesses and pollutants should we dare cook with them now without ventilation is asinine. Less than 5% of homes in America were built after 1970 source -to-advice/how-old-are-americas-houses.shtml I would venture to say that a very, very small portion of those are super efficient homes where air flow is so restricted that it has to be added into the design to achieve. With those homes, there may be a concern. For the other say 99% of homes, there is more than enough air flow to disburse any toxins. I have a family and none of us have complained of dizziness, headaches or other ailments due to use of our gas range or fireplace. In fact we had a house full of family for Thanksgiving with all 4 burners, the stove and the fireplace running and the only complaint that was made was we ran out of gravy. Perhaps as an "advisor" you have sources to actual statistics of number of people and their illnesses, deaths etc.. due to exposure from gas stove and/or vent free fireplace exposure. Not just anecdotal, but actual cases documented and verified.
Why not use candles? Recently during an extended period when temps dropped way below zero our power was out for a few days. We grouped all our candles together. Some were on the kitchen table, others on the living room table and a few in each bathroom to keep pipes from freezing. We shut the bedroom doors and stayed in the main living quarters. When the power came back on, our home was a toasty 70 degrees and we normally keep it at 65. Do you think we were jeopardizing our health? We have gas and could have turned on the oven or boiled water on the stove to even make it warmer but could not vent the gas fumes. Any thoughts? 2ff7e9595c
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