Introduction Hazards and Operability (HAZOP) Studies provide systematic means to identify and assess potential hazards within a process and make recommendations based on the findings to avoid future problems. For this HAZOP study, a two liquefied petroleum gas (LPG) tank system (see Safety Data Sheet in Appendix B) was chosen from the plant facilities of Honeywell Aerospace at Aguadilla, PR. A Facilities Service Contractor for the Company, Sr. Juan Chaparro and Cabo Rojo Gas Engineer, Mr. William Vega, were part of the team that provided the information to support this report. The system set in place by Cabo Rojo Gas & Oil Co. supplies propane to the equipment of the cafeteria inside the location. The tanks have tare weights are of 272.3 and 272.7 lbs. and a volume of 120 gallons. These have a similar valve arrangement as the one shown in Figure 1 according to [1]
manufacturer specifications .
Figure 1. Steel propane tank setup according to Worthington, the manufacturer of the tanks studied.
The two LPG tanks system Process and Instrumentation Diagram (P&ID) is depicted in Figure 2. Some of the valves on the tanks were obviated from the diagram to maintain simplicity of the process. The propane gas system delivers the fuel to 6 pieces of equipment inside the cafeteria kitchen: two industrial ovens, one grill, a deep fryer and two industrial stoves. The system is straightforward: both tanks merg e in a single pipe, containing a regulator pump, two seismic emergency shutoff valves and two pressure relief valves and two butterfly valves along this main line. In the kitchen, this pipe divides into the six feeds that go into the
equipment. As one of the safety precautions, the second butterfly valve (also known as a quarter turn va lve) is shut off every day by the last per son working in the kitchen facilities.
. m e t s y s e n a p o r p f o ) D I & P ( m a r g a i D n o i t a t n e m u r t s n I d n a s s e c o r P . 2 e r u g i F
3 e d o N
2 e d o N
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Hazards and Operability Study
Node 1: Tanks
Propane gas storage (more specifics such as capacity and filling procedures in finished report) and periodic refilling.
Design intention:
More, Higher, Greater
Less, Lower
Temperature
Corrosion
Pressure Flow
Process Parameters
No, Not, None
Vibration
Capacity
As Well As
Part Of
Reverse
Other Than
Sooner Than
Later Than
Where Else
Node 2: Outside valves
Flow regulation (specifics such as propane flow on finished report), propane transport, and control through piping outside of the facility.
Design intention:
More, Higher, Greater
Less, Lower
Temperature
Corrosion
Pressure
Process Parameters
No, Not, None
Flow
Vibration
Capacity
As Well As
Part Of
Reverse
Other Than
Sooner Than
Later Than
Where Else
Node 3: Inside Valves
Flow regulation (specifics such as propane flow on finished report), propane transport, and control through piping inside of the facility. Also gas supply to equipment.
Design intention:
More, Higher, Greater
Less, Lower
Temperature Corrosion
Pressure
Process Parameters
Flow
No, Not, None
As Well As
Part Of
Reverse
Other Than
Vibration
Capacity
Sooner Than
Later Than
Where Else
References [1]"Steel Forklift Cylinders." Worthington Cylinders . N.p., n.d. Web. 22 Feb. 2014. .
http://www.propane101.com
