TB Gas Flashcards
incorrect statement (2) A: Questions concerning the operation of the MSA Altair Digital Gas meter or operational procedures at natural gas incidents can be directed to the Meter room B: Series of three large crosses along the screen under the O2 icon indicates the atmosphere is above 30 percent oxygen C: Series of three "X"s along the screen under the COMB/EX icon indicates the atmosphere is above 100 percent of the LEL D: The action level for indoor operations is 10 percent of the LEL and 20 percent of the LEL for outdoors
A Haz-Mat Battalion
Emergency Procedures Natural Gas add 2
D 10% LEL or greater detected outside or inside; Elevated natural gas readings 20% LEL or greater in unvented, subsurface structures (manhole, sewer)
7 Major Gas Emergency conditions
- What kind of damage to components
- % LEL or greater detected outside or inside
- Elevated natural gas readings (% LEL) in unvented, subsurface structure
- Gas present in how many subsurface structures
- Gas migrating
- Gas leaking or present _
Serious damage to major components of gas infrastructure (master meter, main valves, distribution mains)
10% LEL or greater detected outside or inside
Elevated natural gas readings (20% LEL or greater) in an unvented, subsurface structure (manhole, sewer)
Gas present in two or more subsurface structures (manhole, sewer)
Gas migrating into a bldg from an outside source
Gas leaking inside of a structure and controlling valve cannot be located or is inoperable
Gas leaking or present inside of a wall or void in a structure
Priority Shutoff of valve closure
“All Melted Red MM’s Have Been Eaten Carefully Man”
Appliance
Interior gas riser (2)
Individual Meter valve (2A if NO Master Meter)
Master Meter (when possible, notify Utility first)
Head of service
Building Service valve (found just inside bldg)
Exterior gas riser valve
Curb valve (FD Last resort) Requires Utility consultation
Main valve FD does NOT shut
If a leak is serious enough to consider shutting down _, _, or _ consider treating the incident as a Major Gas Emergency
Master meter valve, Head of Service Valve, or Curb valve Consider Major Gas Emergency
Signal for Major Gas Emergency;
Can IC modify response?
10-75 and 10-80 Code 1 specifying “Major Gas Emergency”
IC may modify assignment to meet incident needs after careful consideration and consultation with Haz Mat Battalion via Cell phone or 800 MHz radio (preferred)
If IC needs to consult with Haz Mat Battalion pertaining to Major Gas Emergency, which method of communication is preferred A. Dept Radio B. Cell Phone C. 800 MHz radio D. Post Radio
C
What is the first priority at a natural gas emergency
Ensure it is NOT a Major Gas Emergency
Secondary is mitigating minor leaks
What shall be used to mark the potential Blast Zone?
Red “Danger do NOT enter” tape
Announce potential blast zone boundaries over the HT and Dept radio
If the leak can be kept at less than _ % LEL, remove ignition sources for gas leak if found;
If not found _% LEL
Less than 80%; If at anytime gas levels reach 80% of LEL or higher, treat as Potential Blast Zone;
If levels cannot be limited to less than 10% LEL and cannot be found, treat as Potential Blast Zone
Are members allowed inside of Potential Blast Zone
Number of members and time spent operating in potential blast zone should be kept to a minimum and allow for rapid evacuation; Potential Blast Zone is considered an exclusion zone for all personnel and shall only be entered for direct, life saving purposes
Do NOT enter potential blast zone to move a rig;
Other agencies should be prevented from entering potential blast zone unless they are involved in direct, life saving procedures; this includes Utility Company
Can FD remove power at emergency gas leaks
If FD members can remove power from the area of the leak before readings reach 80% LEL, it Should be done. If any readings display levels of 80% or higher, the opportunity to cut power has expired
